dbcve.org
FirefoxWeb browser · Mozilla

CVE-2022-3266

MEDIUM · 5.5 CVSS v3.1 Published 2022-12-22
Fix available
A fix is available. Upgrade to 102.3 / 105.0 or later.
See remediation →
58/100
Remediation priority · Elevated
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An out-of-bounds read can occur when decoding H264 video. This results in a potentially exploitable crash. This vulnerability affects Firefox ESR < 102.3, Thunderbird < 102.3, and Firefox < 105.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

An out-of-bounds read vulnerability exists in the H264 video decoding path in Firefox, Firefox ESR, and Thunderbird. The vulnerability occurs during H264 video decoding and can lead to a potentially exploitable crash, allowing an attacker to read memory beyond allocated buffers.

MitigationUpdate affected products to Firefox ESR 102.3+, Thunderbird 102.3+, or Firefox 105+ to patch the vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FirefoxWeb browser
Affected:< 105.0
Firefox EsrWeb browser
Affected:< 102.3
ThunderbirdApplication
Affected:< 102.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Mozilla product
    Open the application and go to Help > About (Firefox or Thunderbird) or type about:firefox in the address bar for Firefox. Note the product name and exact version number.
    Affected if The product is Mozilla Firefox, Firefox ESR, or Thunderbird with a version below 105.0 for Firefox or below 102.3 for ESR and Thunderbird.
  2. Verify the exact version number against affected ranges
    Compare your installed version to these thresholds: Firefox < 105.0, Firefox ESR < 102.3, Thunderbird < 102.3. Check the Help > About dialog for the full version string (e.g., 102.2 or 104.0.1).
    Affected if The installed version falls below the thresholds: Firefox below 105.0, or Firefox ESR/Thunderbird below 102.3.
  3. Confirm H264 video decoding capability is present
    Type about:support in the Firefox address bar and look for 'H264 hardware acceleration' or 'Video Decode' entries under Graphics. For Thunderbird, the same info appears in Help > Troubleshooting Information under Graphics.
    Affected if The application reports H264 decoding support (software or hardware) is available. The vulnerability exists in the H264 decoding path regardless of whether hardware acceleration is used.
  4. Check if the application processes H264 content
    Review your browser activity - if you have visited or received emails containing H264-encoded video content (common in MP4 files, web video, and many email attachments), the vulnerable decoding path was invoked.
    Affected if The application has processed or can process H264-encoded video content, which activates the vulnerable decoding code path.

You are affected if you are running Firefox below version 105.0, or Firefox ESR or Thunderbird below version 102.3, and the application has H264 video decoding capability enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 102.3 / 105.0 or later
Fixed in 102.3105.0
Interim mitigation

Update affected products to Firefox ESR 102.3+, Thunderbird 102.3+, or Firefox 105+ to patch the vulnerability.

Recommended fix High confidence

Firefox 105.0+ | Firefox ESR 102.3+ | Thunderbird 102.3+

  1. 1. Identify which Mozilla product is in use: Firefox (regular), Firefox ESR, or Thunderbird
  2. 2. Check the current version by clicking the menu button (three horizontal lines) > Help > About [Product Name]
  3. 3. For Firefox: Upgrade to version 105.0 or later
  4. 4. For Firefox ESR: Upgrade to version 102.3 or later
  5. 5. For Thunderbird: Upgrade to version 102.3 or later
  6. 6. Restart the application after the update completes
Caveat Minimal risk - security updates within stable release branches typically have no breaking changes; always backup profile data before major updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Firefox Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-3266 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-3266 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data