CVE-2022-3266Public exploit

Application crash via mismatched H264 frame dimensions

Published Dec 22, 2022 · Updated Apr 15, 2025

Out-of-bounds read in Mozilla Firefox before 105, Firefox ESR before 102.3, and Thunderbird before 102.3 allows attackers to crash the application. The Windows Media Foundation decoder retains container or SPS dimensions that can disagree with the decoded output buffer, then creates a video-frame buffer using the stale size. Exploitation requires a user to play a crafted MP4 on Windows; repeated playback terminates the GPU or utility process.

CVSS severity5.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Mozilla Firefox before 105, Firefox ESR before 102.3, and Thunderbird before 102.3 allows attackers to crash the application. The Windows Media Foundation decoder retains container or SPS dimensions that can disagree with the decoded output buffer, then creates a video-frame buffer using the stale size. Exploitation requires a user to play a crafted MP4 on Windows; repeated playback terminates the GPU or utility process.

The record

CVE
CVE-2022-3266
Published
Dec 22, 2022
Updated
Apr 15, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-125, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <105

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <105
Mozilla · Thunderbirdversion=unspecified <102.3
Mozilla · Firefox ESRversion=unspecified <102.3

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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