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Call of Duty: Modern Warfare 4Call of Duty: Modern Warfare 4 · PC · version Launch (Oct 2026)

Constant packet loss and lag spikes in online matches

UnconfirmedUnpatched

Updated

Since launch weekend, some players get MW4's packet loss, packet burst and latency variation warnings every few seconds in Multiplayer and DMZ, with lag and stutter, even at low, steady ping on wired connections, while their other online games run normally. Reports come mostly from PC and began on October 24. In DMZ, players say the lag got them killed or disconnected them mid-mission. No acknowledgement from Infinity Ward found. Frame-rate stutter is a separate issue.

Lifecycle

Reported · stage 1 of 5

4days open

Since first report

  1. Reported (reached) · now
  2. Confirmed (not yet)next
  3. Acknowledged (not yet)—
  4. Partial (not yet)—
  5. Patched (not yet)—
In current stage 4d
Workaround none yet
Game
Call of Duty: Modern Warfare 4
Platform
PC
Affected version
Launch (Oct 2026)
Kind
Bug
Confirmation
Unconfirmed
Patch status
Unpatched
First reported
Last updated
Latest fix or workaround
None on the record
How we label issues

Kind

  • Exploit: Repeatable and clearly advantageous to the player using it; essentially cheating.
  • Bug: Everything else: crashes, launch errors, broken features, visual or audio faults.

Confirmation

  • Confirmed: A developer or official account acknowledged it, an official known-issues board lists it, it appears in official patch notes, or 100+ corroborating posts on X were actually counted.
  • Unconfirmed: None of the above yet. Press articles are reports and never confirm an issue on their own.

Patch status

  • Unpatched: Known and open; no fix has been claimed.
  • Reported as unpatched: Players credibly report it persisting, including after a fix claim that never appeared in patch notes.
  • Partially patched: Official patch notes list a fix, but credible later reports say it still happens, or the notes only cover part of it.
  • Reported as patched: A developer, official account or player says it is fixed, but no official patch notes list it.
  • Patched: Official patch notes (a Steam news post or the publisher's patch notes page) list the fix, and nothing credible says it still happens.

Active means still affecting players: Unpatched, Reported as unpatched or Partially patched. Patched and Reported as patched issues are closed.

Estimated impact runs from 0.1 to 9.9 with one decimal. xploitr sets it from the rubric below. Factors: advantage to other players, reach, play blocked or progress lost, frequency, and whether a reliable workaround exists. Patched issues keep their historical impact.

Signed-in community members can report new issues and suggest status changes, such as Fixed or Still unpatched, with their platform, version and a source. Every report and suggestion is reviewed by an editor before anything on the record changes. A new issue is published only when the report has at least three independent sources (distinct accounts, or distinct sites for web pages, after blocked sources are removed), unless the owner approved that issue by hand. Approved input appears as a dated Update from the xploitr community source on the issue's timeline, credited to the member's username (reports can opt out and stay anonymous); nothing is counted or published automatically.

Impact bands

  • 0.1–2.9 Low: Cosmetic, audio, text and UI glitches with no effect on play.
  • 3.0–4.9 Moderate: Narrow gameplay bugs or small exploits, rare or with a workaround.
  • 5.0–6.9 Elevated: Bugs most players in a mode notice: hit registration, desync, balance-breaking damage.
  • 7.0–8.4 High: Widely abused competitive or economy exploits; crashes many players hit.
  • 8.5–9.9 Severe: Launch blockers, widespread progress or item loss, exploits that break the game for everyone.

Each issue has a dated timeline of updates (report, acknowledgement, announcement, fix, workaround). Update summaries are our own words; quotes and excerpts are the source's words, or our English translation when marked.

Estimated impactEstimated impact 4.5 out of 9.9, ModerateOur estimate from how many players it reaches and what it costs them.

Updates · 8

Show all 8 updates
  1. Report

    Oct 28: another player has the same lag in DMZ.

    Community report · Steam · Forum reply ·
    “Having the same issues with lag in DMZ.”
    Community report · Steam · Forum reply · Open source
  2. Report

    Oct 28: another player has the same lag and is asking for a refund.

    Community report · Steam · Forum reply ·
    “literally same, im requesting a refund.”
    Community report · Steam · Forum reply · Open source
  3. Report

    Oct 28: another player has the same problem.

    Community report · Steam · Forum reply ·
    “same here”
    Community report · Steam · Forum reply · Open source
  4. Report

    Oct 28: a PC player gets packet burst, packet loss and latency variation warnings that make the game close to unplayable, unlike MWII and MWIII on the same connection.

    Community report on reddit ·
    “Got the game today but it is borderline unplayable for me so far.”
    Community report on reddit · Open source
  5. Report

    Oct 29: a player on a stable wired 1 Gbps connection gets constant packet loss warnings and stutter they say feels server-side; their other online games are fine.

    Community report on reddit ·
    “it feels like the game stutters on the server side.”
    Community report on reddit · Open source
Sources · 88 CommunityCommunity reportSteam · Forum thread+ 7 similar community reportsHide
Community reportSteam · Forum thread
“now since yesterday I am getting packet losses and latency issues every game like every gunfight.”
  • Community reportSteam · Forum threadOpen
    “playing DMZ and 2 missions in a row i basically disconnected.”
  • Community reportSteam · Forum threadOpen
    “in mw4 i literally cant go a game without lagging and having packet loss every 5 seconds”
  • Community reportSteam · Forum replyOpen
    “Having the same issues with lag in DMZ.”
  • Community reportSteam · Forum replyOpen
    “literally same, im requesting a refund.”
  • Community reportSteam · Forum replyOpen
    “same here”
  • Community report · redditOpen
    “Got the game today but it is borderline unplayable for me so far.”
  • Community report · redditOpen
    “it feels like the game stutters on the server side.”
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