dbcve.org
FirefoxWeb browser · Mozilla

CVE-2022-40962

HIGH · 8.8 CVSS v3.1 Published 2022-12-22
Fix available
A fix is available. Upgrade to 102.3 / 105.0 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable 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
Mozilla developers Nika Layzell, Timothy Nikkel, Sebastian Hengst, Andreas Pehrson, and the Mozilla Fuzzing Team reported memory safety bugs present in Firefox 104 and Firefox ESR 102.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. 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 · high confidence

Multiple memory safety bugs in Firefox 104 and Firefox ESR 102.2 allowed memory corruption that could potentially be exploited for arbitrary code execution. The vulnerabilities were discovered through fuzzing and developer review.

MitigationUpdate affected products to Firefox 105, Firefox ESR 102.3, Thunderbird 102.3, or later versions to patch the memory safety vulnerabilities.

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
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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
    Check if Firefox, Firefox ESR, or Thunderbird is installed. On Windows, look in Program Files or Program Files (x86). On macOS, check /Applications. On Linux, check /usr/bin for firefox or thunderbird.
    Affected if Any of these three products is installed
  2. Determine the installed Firefox version
    Open Firefox, go to Help > About Firefox, or type about:support in the address bar. The version number is displayed on the page that opens.
    Affected if The version displayed is below 105.0 (for example, 104.x or earlier)
  3. Determine the installed Firefox ESR version
    Open Firefox ESR, go to Help > About Firefox, or type about:support in the address bar. Look for the ESR designation in the version string.
    Affected if The version displayed is below 102.3 (for example, 102.2 or earlier)
  4. Determine the installed Thunderbird version
    Open Thunderbird, go to Help > About Thunderbird, or type about:support in the address bar.
    Affected if The version displayed is below 102.3 (for example, 102.2 or earlier)

The user is affected if any installed Firefox version is below 105.0, any Firefox ESR version is below 102.3, or any Thunderbird version is below 102.3.

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 105, Firefox ESR 102.3, Thunderbird 102.3, or later versions to patch the memory safety vulnerabilities.

Recommended fix High confidence

Firefox 105.0, Firefox ESR 102.3, Thunderbird 102.3

  1. Open Firefox/Thunderbird and navigate to Help > About [Application Name]
  2. If an update is available, the application will automatically check for and download updates
  3. Click 'Update' to download and install the update
  4. Restart the browser/application after the update completes
  5. Alternatively, download the latest version from the official Mozilla website: https://www.mozilla.org/
  6. For enterprise deployments, update via your software distribution/management system to the fixed versions (Firefox 105.0, Firefox ESR 102.3, Thunderbird 102.3)
Caveat Standard browser upgrade; minor extension compatibility issues may occur with older add-ons

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
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-40962 — 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-2022-40962 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