MW3 Season 1 update patch notes: New 6v6 maps, weapons, Assassin’s Vest Perk, more

Modern Warfare 3 players are set to receive a ton of content with the Season 1 update. Here’s everything you need to know about MW3 Season 1, including patch notes, new maps, Perks, Killstreaks, and the new Zombies Act Missions.

Modern Warfare 3 players are currently exploring the game’s extensive content. This includes discovering a variety of new weapons, the new Zombies mode set in the MW universe, the inclusion of the MW2 2009 map roster, and various other elements.

While a big chunk of MW2 items are carrying over to Modern Warfare 3, players are treated to even more content with the Season 1 update. Like most seasonal updates, the devs have brought weapons, Operators, a Battle Pass, and more to the multiplayer experience.

Here’s everything you need to know about Modern Warfare 3 Season 1 including the full patch notes.

• Release date
• New maps
• New weapons
• MW3 Season 1 Warzone integration
• MW3 Season 1 patch notes

Modern Warfare 3 Season 1 release date

Modern Warfare 3 Season 1 goes live on Wednesday, December 6 at 9 AM PT / 12 PM ET / 5 PM GMT.

All new maps in MW3 Season 1

Modern Warfare 3 Season 1 deploys players into three new 6v6 maps and one 2v2 map. Three of the maps are available with the Season 1 update, while the fourth map, Rio, will arrive in-season.

• Greece (6v6)
• Meat (6v6)
• Training Facility (2v2, Gunfight)
• Rio (6v6, in-season release)

Training Facility is a new Gunfight map debuting in MW3 as the mode makes its way to the game in Season 1. Gunfight is a small-team mode that takes players into the new Training Facility map and four other Gunfight arenas from MW2:

• Alley
• Blacksite
• Exhibit
• Shipment

Modern Warfare 3 Season 1 new weapons

Five new weapons arrive during the MW3 Season 1 update, with three arriving at launch and the remaining two in-season.

Check out all the new weapons for Modern Warfare 3 Season 1 below:

• RAM-7 (AR, Launch)
• TAQ Evolvere (LMG, In-Season)
• XRK Stalker (Sniper Rifle, Launch)
• HRM-9 (SMG, In-Season)
• Stormender (Launcher, Launch)

MW3 Season 1 Warzone integration

Modern Warfare 3 Season 1 brings the new Warzone Urzikstan map. While separate from Modern Warfare 3, the first season introduces the next generation of Warzone.

Taking place on the brand-new Urzikstan map, this update for Warzone brings all of Modern Warfare 3’s content, like Operators and weapons, and some of its mechanics to the battle royale.

This is everything the MW3 Season 1 brings into the game, and with a lot of new content to tackle, players should expect a packed season with tons of new options for their long multiplayer sessions.

MW3 Season 1 patch notes

NEW MAPS

Look for the Meat 24/7 Playlist to debut during the first week of Season 1, with other exciting Playlists expected in the weeks ahead. Another all-new 6v6 map, Rio, is expected to launch in-season

• Greece
  • Test your mettle in a once-idyllic coastal town, where waters at the shore lap at the hull of a burning yacht, signaling disaster.
• Meat
  • Deploy to the West Coast for some fast-paced butchery, in a compact map centered around the East Bay Meats slaughterhouse.
• Training Facility (Gunfight)
  • Challenge another duo within the remains of an old warehouse, now repurposed as part of Konni Group’s training facilities.

NEW KILLSTREAKS

Do you have what it takes? Two all-new Killstreaks are available to dominate the battlefield in Season 1.

• EMP
  • Electromagnetic pulse to disrupt enemy killstreaks and equipment.
  • Earned via 13 Kills, 1,625 Score, or Care Packages.
• Swarm
  • Deploys a large number of mosquito drones to provide blanket coverage over the entire area.
  • Earned via 15 Kills, 1,875 Score, or Care Packages.

NEW PERK

The Assassin Vest is a powerful new addition to Loadouts in Season 1, but be wary, each Vest comes equipped with critical tradeoffs.

• Assassin Vest
  • Kills don’t display skulls. Immune to UAV and enemy radar effects (including while stationary).

NEW MODES

Two fan-favorite Modes return at the start of Season 1! Gunfight is even equipped with its own selection of new and Carry-Forward Maps. Look for additional Modes throughout the Season.

• All or Nothing
  • Players start with Throwing Knives and an empty Pistol. Perks are earned by eliminating other players and staying alive.
• Gunfight
  • Small team, multi-round cage matches. First team to reach the round limit wins.

GLOBAL

NEW WEAPONS

The following Weapons are new to the entirety of the Modern Warfare III offering as of Season 1.

• RAM-7 (Assault Rifle)
  • Exceptionally compact, this bullpup assault rifle sports a lightweight, polymer frame and is chambered in versatile 5.56.
  • Unlockable via Sector A7 of the Season 1 Battle Pass
• XRK Stalker (Sniper Rifle)
  • Stalk your prey and lay them out with this tactical sniper rifle chambered in .50 Cal.
  • Unlockable via Sector A4 of the Season 1 Battle Pass
• Stormender (Launcher)
  • This state-of-the-art weapon system fires a localized EMP on a slight delay. Destroys tactical and lethal equipment and temporarily disables other electronic devices.
  • Unlockable via Sector A12 of the Season 1 Battle Pass

NEW AFTERMARKET PARTS

In addition to new weaponry, players will see brand new Aftermarket Parts earned via the Battle Pass, Armory Unlocks, and Weekly Challenges.

• JAK Purifier
  • An underbarrel flamethrower. What more needs to be said? Burn it all down.
  • Compatible with: MTZ-556, Holger 556, DG-56, SVA 545, RAM-7, MTZ-762, BAS-B, Sidewinder, Riveter 
• JAK Ettin Double Barrel Kit
  • This kit creates two stacked barrels that fire simultaneously. This offers twice as much down-range damage at the cost of some accuracy. 
  • Compatible with: AMR9 (Submachine Gun)
• JAK Thunder LMG Kit
  • Dominate lanes and hold objectives with this LMG conversion kit that brings a large capacity magazine and ramps in fire rate the longer you hold down the trigger.
  • Compatible with: Sidewinder (Battle Rifle)
• JAK BRB
  • This compensator borders on excessive, offering a phenomenal reduction to recoil while significantly increasing muzzle report, resulting in an extended red dot on enemy radars.
  • Compatible with: Many Assault Rifles, Submachine Guns, Battle Rifles, Marksman Rifles, and Sniper Rifles. 
• JAK Bullseye
  • Very low-profile dot Optic. Limited interference from framework offers an exceptionally clear sight picture. 
  • Compatible with: Most weapon categories
• JAK Glassless Optic
  • This small, glassless reflex Optic offers a crisp and clear sight picture for snappy target acquisition. 
  • Compatible with: Most weapon categories
• JAK Signal Burst
  • A conversion kit designed for accuracy and controllability with four-round bursts.
  • Compatible with: Holger 556 (AR)
• JAK Beholder Rifle Kit
  • A long and heavy barrel that offers the best increase to range. Improves recoil control and damage range, converting this Handgun into a single-shot Rifle. 
  • Compatible with: TYR (Handgun)
• JAK Headhunter Carbine Conversion
  • Rival Assault Rifles with this three-round burst conversion kit that excels at mid range combat. 
  • Compatible with: Rival-9 (Submachine Gun)

NEW OPERATORS

Nolan and Dokkaebi, two KorTac Operators, lead the charge in the Season 1 offering… But a mysterious force, known only as Abolisher, looms in the background.

• Abolisher BlackCell (SpecGru)
  • [Redacted]
• Dokkaebi (KorTac)
  • Ari was born in South Korea to a family of gifted engineers. Tired of hiding from North Korean agents, she hacked into the South Korean Military’s private contacts and found the global Kortac Faction.
• Nolan (KorTac)
  • Recently anointed as Vladimir Makarov’s right hand man, Captain Andrei Nolan executes both plans and enemies with ferocious precision in the name of igniting a long-awaited war between East and West.

NEW EVENTS

We’ll be talking about what Zombie Santa is bringing to town in patch notes that will release closer to when the event launches over the holidays. Stay tuned!

NEW BATTLE PASS

A brand new Battle Pass arrives with the Season 1 bringing a variety of Operator Skins, Weapon Blueprints, and more.

For more information about the full Battle Pass offering and Black Cell Bundle, check out the full breakdown on the official Call of Duty blog here.

NEW PC FEATURES

GeForce RTX gamers can activate pre-game full ray tracing, also known as path tracing in pre-game lobbies, enabling you to see your characters, skins, vehicles, and weapons in an entirely new light.

All GeForce RTX gamers can activate Path Tracing via the Video options menu, and doing so will automatically enable NVIDIA DLSS 3.5 with DLSS Ray Reconstruction.

MULTIPLAYER

UIX

• New Features & Quality of Life
  • Player health and stamina are now represented by dynamic bars on the HUD.
    • Note: This feature is only available in Multiplayer and Zombies.
  • Faction assignment will now appear as a splash at the start of each match.
  • Added Upper Legs Damage and Empty Reload Quickness statistics to the Details widget in the Gunsmith.
  • Increased decimal precision of the Flinch Resistance stat in the Details widget in the Gunsmith.
  • Added icons in the Gunsmith to represent which title an Attachment originates from.
  • Reduced volume of the Multi-Kill and Medal splash sound effects.
• Bug Fixes
  • In Search and Destroy, hovering a bombsite on the Tac-Map will no longer reveal when a player is actively defusing.
  • Addressed multiple issues in Private Matches that caused players to be kicked back to the Main Menu.
  • Hovering an equipped Killstreak will no longer kick the player back to the Multiplayer menu.
  • Resolved a font rendering issue that caused text to be improperly displayed.
  • Improved performance of Social features for players with large Friend counts.
  • Resolved an issue in which the incorrect Weapon would be featured in the overlay of Killcams.
  • Kill Counter will now properly function with streaks beyond 120 Kills.
  • Reduced hitching that infrequently occurred while transitioning between menus.
  • Addressed an issue that caused the application to freeze while editing a Loadout.
  • Resolved a crash that could occur prior to viewing an After Action Report.
  • Addressed an issue that caused a crash while reporting a player.
  • Lockpick (Operator) can now be equipped, where available, without using the Quick Equip option.
  • Scrolling menus while in splitscreen will no long result in the cursor appearing off-screen.
  • Improved readability of the timer below the Event tab.

GAMEPLAY

• Movement
  • Added a delay following multiple rapid stance transitions to prevent exploitable repetition.
    • Crouch to Stand: 150ms
    • Prone to Stand: 600ms
• Spawns
  • Improved spawn protection against enemy Equipment and Killstreaks.
  • In Hardpoint, several adjustments have been made to improve the flow of combat and increase control of team-owned areas.

We’ve introduced a delay to stance transitions to combat a movement exploit commonly referred to by players as “snaking.” We’ll monitor the impact of these changes and continue to address feedback where appropriate.

WEAPONS & ATTACHMENTS

• Decreased hipfire spread penalty incurred while firing/moving for all Submachine Guns.

» Assault Rifles «

• MTZ-556
  • Increased maximum hipfire spread while standing by 10%.
  • Increased maximum hipfire spread while crouched by 6%.
  • Increased hipfire spread penalty incurred while firing by 10%.
  • Increased hipfire spread penalty incurred while moving by 4%.
  • MTZ Natter Heavy Short (Barrel)
    • Decreased hipfire spread benefit by 5%.
  • Bruen Thunder V9 (Stock)
    • Decreased hipfire spread benefit by 6%.

» Battle Rifles «

• BAS-B
  • Increased damage multipliers in semi-auto fire type to intended values.
    • Lower-Torso: 1x to 1.2x
    • Arm & Hand: 1x to 1.35x
• Sidewinder
  • Decreased aim down sights time from 280ms to 265ms (-5%).
  • Tempus Predator Precision (Barrel)
    • Increased gun kick control benefit by 5%.
  • Huntsman Series-R Integrated Suppressor (Barrel)
    • Increased gun kick control benefit by 7%.
  • RB Borealis Grip (Rear Grip)
    • Increased gun kick control benefit by 5%.

» Submachine Guns «

• Striker
  • Decreased sprint to fire time from 110ms to 100ms (-9%).
  • Decreased aim down sights time from 230ms to 215ms (-7%).
  • Striker Stubby (Barrel)
    • Added 9% aim down sights time benefit.
• WSP Swarm
  • Decreased sprint to fire time from 110ms to 88ms (-20%).
  • Decreased aim down sights time from 190ms to 175ms (-8%).
• Striker 9
  • Decreased sprint to fire time from 110ms to 100ms (-9%).
  • Decreased aim down sights time from 225ms to 205ms (-9%).
  • Striker Stubby (Barrel)
    • Added 9% aim down sights time benefit.

» Shotguns «

• Lockwood 680
  • Tac-Stance will no longer reduce damage pellet count.

» Marksman Rifles «

• MCW 6.8
  • Equipping the Full-Auto Conversion Kit and 60rnd Drum Magazine will no longer result in a broken aim down sights animation.

» Melee «

• Riot Shield
  • Increased melee damage from 50 to 75 (+50%).
  • Added a 10% movement speed penalty while stowed.

» Attachments «

• S-37C DL Breacher Device (Muzzle)
  • Decreased hipfire spread benefit by 14%.
  • Resolved an issue that prevented one-hit melee kills in round-based Modes.
• Bruen Tactical Vertical Grip (Underbarrel)
  • Decreased hipfire spread benefit by 8%.
• Hollowpoint (Ammunition)
  • Decreased inflicted sprint penalty time from 800ms to 200ms (-75%).

Modern Warfare II (Carry-Forward)

• Increased reserve ammunition for all Weapons to MWIII standards.
• Decreased hipfire spread benefit of Underbarrel vertical grips by 5-12%.
• Decreased hipfire spread benefit of applicable Lasers by 2-5%.

» Assault Rifles «

• M4
  • Increased maximum damage from 28 to 35 (+25%).
  • Decreased head and neck damage multipliers from 1.37x 1.1x (-20%).

» Battle Rifles «

• TAQ-V
  • Increased lower-torso, leg, and foot damage multipliers from 0.8x to 1.1x (+38%).

» Submachine Guns «

• Vaznev-9K
  • Increased near-medium damage from 29 to 30 (+3%).
• ISO 45
  • Increased maximum damage from 30 to 33 (+10%).

» Shotguns «

• KV Broadside
  • Increased far-medium damage range from 9m to 10m (+8%).
  • Decreased aim down sights spread slightly.

» Light Machine Guns «

• RAAL MG
  • Decreased aim down sights time from 470ms to 390ms (-17%).
  • Decreased sprint to fire time from 375ms to 320ms (-15%).
  • Decreased tactical sprint to fire time from 496ms to 416ms (-16%).
• 556 Icarus
  • Increased maximum damage from 28 to 34 (+21%).
  • Decreased head damage multiplier from 1.4x to 1.1x (-21%).

» Marksman Rifles «

• SP-R 208
  • Increased maximum damage range from 15m to 20m (+28%).
  • Decreased aim down sights time from 370ms to 340ms (-8%).

» Handguns «

• Basilisk
  • Increased maximum damage range from 5m to 7m (+35%).
  • Increased near-medium damage range from 6m to 15m (+140%).
  • Increased far-medium damage range from 17m to 23m (+32%).

PROGRESSION

• Corrected unlock requirement descriptions for multiple Weapon Attachments.
• Revised conditions for multiple unlocks that caused Attachments to be unavailable at the expected Weapon level.
• Associated weaponry will now be properly included in the Camo unlock splashes.
• Player Rank
  • Increased Level cap from 55 to 250, enabling players to reach Prestige 5.
    • At each Prestige, a new animated icon is unlocked.

CUSTOMIZATION

• Increased animation rate of the Priceless and Interstellar Completionist Camos.

MAPS

• Derail
  • Swapped Attacker and Defender initial spawn positions in Control.
• Estate
  • Improved bullet penetration through the staircase in the Lodge.
  • Adjusted collision to prevent players can accessing an unintended location near the Front Entrance of the Lodge.
• Highrise
  • Improved ambient audio reverberation in the Mechanical Room.
  • Deprioritized spawn points distant from the objective in Hardpoint.
• Karachi
  • Players will now spawn on the correct side of the map assigned to their team in Cutthroat.
• Quarry
  • Added collision near the Offices to prevent players from reaching unintended locations.
  • Addressed an issue that caused players to spawn in unfavorable conditions in the Hardpoint game mode.
• Skidrow
  • Enemy player nameplates are no longer visible through certain surfaces in the Apartments.
• Terminal
  • Added additional spawn points in Free-for-All mode to improve player experience.
  • Improved ability to gauge spawn selection quality in all Modes.
  • Relocated a spawn point that placed players outside of the playable area.
• Scrapyard
  • Reviewed objective capture points to prevent players from capturing from unintended locations in Hardpoint and Control modes.
  • Added additional spawn points in Free-for-All mode to improve player experience.
• Sub Base
  • Improved ambient audio reverberation in the Power Station.
  • Swapped Attacker and Defender initial spawn positions in Control.
• Orlov Military Base (Ground War)
  • Improved AI Bot ability to navigate the environment in Invasion mode.
• Operation Spearhead (War)
  • Added collision near the Hotel to prevent players from exiting the playable area.
  • Added collision near the Corner Shop to protect players in their spawn area.
  • Addressed an exploit involving environmental turrets that allowed players to reach unintended locations.

MODES

• Ground War
  • Pre-game lobby countdown timer will no longer reset when a player leaves.
• Search and Destroy
  • Increased Player XP earned for several score events.
    • Kill: 500 XP
    • Assist: 200 XP
    • Shield Assist: 400 XP
    • Headshot: 1,000 XP
    • Plant: 1,000 XP
    • Defuse: 1,000 XP (+ 250 XP for Last Alive)
    • Ninja Defuse: 1,250 XP (+ 250 XP for Last Alive)
• War
  • Players who join an in-progress match can no longer be placed on a full team.
  • Decreased tank escort phase time limit from 6m to 5m.
  • Joining an in-progress match during the ending cinematic sequence is no longer possible.

EQUIPMENT

• Throwing Star (Lethal)
  • Addressed an issue that allowed one-hit kills without a Headshot.
• EMD Grenade (Tactical)
  • Prompt to remove tracker will no longer persist after death.

FIELD UPGRADES

• Deployable Cover
  • Previous deployments will now be destroyed upon new deployment as the maximum has been limited to 1.
• Trophy System
  • Mosquito Drone (Killstreak) will no longer be targeted.

KILLSTREAKS

• Juggernaut Recon
  • Addressed an exploit that allowed players to fire Loadout Weapons with unlimited ammo.
• Precision Airstrike
  • Players will now properly look through the binoculars in third-person view.
• Remote Turret
  • Implemented safeguard measures to prevent players from becoming stuck with the tablet in hand.

VEHICLES

• NSTV
  • Increased traction control to improve handling on muddy surfaces.
• Razor Tank
  • Decreased maximum forward speed by 14%.
  • Increased maximum reverse speed by 20% to match forward speed.
  • Increased turn speed by 40% to allow for tighter turns.
  • Increased ability to accelerate on sloped surfaces.

ZOMBIES

SEASON 1 CONTENT

Story Act and Mission

• Act IV and a new Story Mission are immediately available for all players at the start of Season 1.
• A massive gateway has appeared in the Exclusion Zone. Investigate the area and engage in new end-game content.

Dark Aether Rifts

• Dark Aether Rifts bring rewards to those who brave their challenges.
  • These otherworldly labyrinths are located inside the Dark Aether, where players and their squad have a limited time to complete a series of increasingly chaotic objectives to earn exceptional rewards. Find Sigils to enter the Dark Aether Rifts and face a new level of challenge!
• Dark Aether Rifts are unlocked by solving a hidden quest, which activates after completing the new Season 1 Story Mission.

Wonder Weapon: V-R11

• The V-R11 has been added to Modern Warfare Zombies.
  • Shoot zombies and transform them into humans, or blast humans to mutate them into friendly zombies.
  • Players receive a buff when shot.
  • The V-R11 has been added to the Mystery Box in Modern Warfare Zombies.
  • V-R11 Weapon Cases are now available via loot.

Acquisitions and Schematics

• Dog Bone
  • Consume the Dog Bone to summon the strongest friendly Hell Hound companion. The pet Hellhound will follow you and attack nearby threats until its health runs out.
• Golden Armor Plate
  • Consuming the new Golden Armor Plate replaces the Armor Carrier with Plates that automatically repair over time, in addition to providing the user additional damage resistances.
• Aether Blade
  • The Aether Blade is a special Throwing Knife with infinite ammo and a boomerang-like combat style. After striking an enemy, the Aether Blade locates the next nearest enemy to hit before returning to its Operator.

Prestige Challenges

• Season 1 allows you to level up past Rank 55 into Prestige Ranks that persist across seasons. 
• Beginning in Season 1, reaching Rank 56 will unlock Prestige 1. Achieving this unlocks rewards and a set of challenges in Modern Warfare Zombies — complete those challenges to unlock multiple exclusive Calling Cards.
• For more details on Prestige Challenges, visit the Challenges and Seasonal Progression section of the Season 1 Announcement Blog.

Season 1 Battle Pass Weapons

• The XRK Stalker, RAM-7, and Stormender are available in Modern Warfare Zombies loadouts once unlocked via the Season 1 Battle Pass.

Global Changes

• Season 1 updates are not limited to just Zombies! Please reference the Global Section above for weapon balancing changes and more.

MAPS

Urzikstan

• Various visual map fixes.

WEAPONS

» Wonder Weapons «

• The Scorcher
  • The Scorcher’s launch ability will automatically fire when a player reaches their maximum charge under low ammo conditions.

» Assault «

• DG-58
  • Addressed an issue that prevented camos from applying in the customization tab in loadout menus.

» Weapon Cases «

• All Weapon Cases
  • Closed a duplication exploit.

MISSIONS

Hostile Takeover

• Addressed an issue that prevented some safes from progressing this Mission.
• Adjusted the description of this Mission in the Mission Select menu to state that Greene wants Players to hit “Terminus” instead of “Deadbolt.”

Merc Cleanup

• Mercenaries killed from long distances inside Merc Camps will now progress this mission.

Shocked

• This Mission now requires players to shock five separate Special zombies instead of shocking the same Special zombie multiple times.

Storm the Castle

• The required mission item will always drop when the Warlord is killed.

GAMEPLAY

Contracts

• Defend Ground Station
  • Addressed an issue that prevented the timer for the Defend Ground Station contract from appearing if players previously completed the same contract in a single session.
  • Mercenaries will now continue to fight Players after completing the Defend Ground Station contract.
• Eliminate Bounty Target
  • HVTs lured far away from their original spawn location in an attempt to exploit their behavior will now return faster to their spawn and heal more.
• Outlast
  • Enemies no longer spawn if players are not progressing the contract.
• Raid Weapon Stash
  • Enemies no longer spawn if players are not progressing the contract.
• Spore Control
  • Adjusted Spores to prevent them from spawning on a player, resulting in an instant death.

Acquisitions

• General
  • Addressed an issue where players could store more Acquisitions in the stash than intended.
• Aether Tools
  • Addressed an issue that prevented Aether Tools from applying if a player was driving a vehicle.
• Ammo Mods
  • Addressed an issue that prevented Ammo Mods from applying if a player was driving a vehicle.
• Perk-A-Colas
  • Tombstone Soda
    • Addressed an issue where Tombstones could spawn under the map.
    • Addressed an issue where Tombstones could spawn in the center of the map instead of where a player previously died. 
    • Addressed an issue where sometimes players would not obtain their essence when interacting with a Tombstone.
    • Closed various duplication exploits associated with Tombstone Soda.
• Ammo Mods
  • Brain Rot
    • Players will now receive essence when a Brain Rotted Zombie kills other Zombies or dies.

Looting

• Various fixes for locations on the map where players could not loot items.

Exfil

• Launch
  • More formidable enemies have been added to the Exfil experience in all zones.
  • Addressed a rare issue that prevented the Hilltop Exfil helicopter from landing.
• In-Season
  • All exfils will increase the number of enemies spawned, with the Final Exfil receiving a significant boost to enemy count and enemy types.

General

• Ammo Caches will now always fully refill applicable player ammo reserves.
• Addressed an issue that allowed players to die instantly if they ran and slid into a Dog House.
• Players will no longer be able to hide inside a Dog House.
• Closed an out-of-bounds location that allowed players to stay alive outside the playable space.
• Addressed an issue where Player selected Operator skins would change upon entering a vehicle.

ENEMIES

Zombies

• Disciples
  • General
    • Addressed multiple issues that allowed Disciples to behave erratically, such as becoming stuck high in the air or on objects.
  • The Stormcaller
    • Addressed an issue that allowed The Stormcaller to die instantly from the Blood Burner’s Aether Pulse.
• Hell Hounds
  • Hell Hound flame particles will disappear if a Hell Hound does not spawn.
• Zombies
  • General
    • Adjusted spawns to prevent Zombies from spawning on top of fences.
    • Adjusted pathing to address exploits or incorrect pathing.
  • Light Armored Zombies
    • Addressed an issue that allowed Light Armored Zombies to receive more headshot damage than intended.

EQUIPMENT

Lethal Equipment

• Experimental Gas Grenade
  • Damage against Aether Worms has been reduced.

Tactical Equipment

• Decoy Grenades
  • Reduced the number of Decoy Grenades that can be stacked or equipped  from 3 to 2.
  • Reduced Decoy Grenade duration from 8 seconds to 6.

KILLSTREAKS

Juggernaut

• Addressed an issue where players could destroy an Exfil helicopter by calling in a Juggernaut suit crate on top of it.

Sentry Turret

• Players can no longer kill themselves or others when placing down a Sentry Turret.

CUSTOMIZATION

Camos

• Borealis (MWIII) and Bioluminescent (MWII) Update.
  • Increased the animation rate of the Borealis and Bioluminescent Completionist Camos

UIX

• Player health and stamina are now represented by dynamic bars on the HUD.
• Addressed an issue that prevented pings on looted items in caches from disappearing automatically.
• Addressed an issue where players who attempted to equip a Mission Reward in the Gear tab would sometimes equip the wrong item.
• Addressed an issue where objective titles would occasionally not display while loading into a match.
• Addressed an issue where objective text would occasionally display outside its panel while loading into a match.
• Addressed an issue where players would be returned to the lobby screen when selecting “Activate Armory Unlock” on a locked Tactical or Lethal equipment item.

PROGRESSION

Achievements

• The First Step
  • Players can now unlock “The First Step” for reaching level 55 in Modern Warfare Zombies. Previously, players would need to enter the Multiplayer menu to obtain the achievement.

Camos

• Completionist Camos
  • Golden Enigma (MWIII) & Golden Ivory (MWII) Update
    • We’ve released a fix that allows Players to complete the Golden Enigma and Golden Ivory Completionist Camos with Blueprint weapons and Custom Mods.

AUDIO

Battle Chatter

• “Friendly Fire” Operator chatter will play less frequently.

STABILITY

• Adjustments have been made to better ensure players keep their loadout and rucksack inventory if they do not successfully deploy into a match.
• Added various crash and stability fixes.

For more on MW3, check out some of our other guides:

Modern Warfare 3 War mode explained | Modern Warfare 3 Zombies Zones explained | How to get MGB Tactical Nuke Killstreak in Modern Warfare 3 | When is Ranked Play coming to Modern Warfare 3? | Best controller settings for Modern Warfare 3 | Best FOV settings for Modern Warfare 3 | How to fix packet burst in Modern Warfare 3

Source: Activision