CVE-2023-29535 — Following a Garbage Collector compaction, weak maps may have been accessed befor

Following a Garbage Collector compaction, weak maps may have been accessed before they were correctly traced. This resulted in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10,

01What is this vulnerability?

Following a Garbage Collector compaction, weak maps may have been accessed before they were correctly traced. This resulted in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10, Firefox for Android < 112, and Thunderbird < 102.10.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2023-06-02T17:15:12.433
• Last modified: 2026-08-19T15:29:21.807

09References

• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=1820543
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-13/
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-14/
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-15/
• bugzilla.mozilla.org — https://bugzilla.mozilla.org/show_bug.cgi?id=1820543
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-13/
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-14/
• www.mozilla.org — https://www.mozilla.org/security/advisories/mfsa2023-15/