CVE-2026-124897: Use-after-free in the JavaScript · GC component
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 153.7 : patch mozjs52 soon.
Data as of 13 Nov 2026, 22:47 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 8.8 |
|---|
- Patch
- Available – fixed in 153.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSmozjs115pkg:deb/ubuntu/mozjs115?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs78pkg:deb/ubuntu/mozjs78?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSmozjs91pkg:deb/ubuntu/mozjs91?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users and administrators should upgrade affected Mozilla Firefox and Thunderbird products to Firefox 160, Firefox ESR 153.7, Thunderbird 160, or Thunderbird 153.7 or later versions where this vulnerability is fixed. Applying these official updates fully mitigates the risk. No additional mitigations are required as the issue is resolved by the vendor's official patches.
Description
CVE-2026-124897 is a use-after-free vulnerability in the JavaScript garbage collection (GC) component of Mozilla products. This flaw was addressed and fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7. The vulnerability has a high severity rating with a CVSS score of 8.8, indicating it could lead to significant impact if exploited. There are no known exploits in the wild at this time.
References
- ubuntu.com/security/CVE-2026-124897 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-124897 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-125/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-127/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-129/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=2082186 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-125/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-127/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-128/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-129/ (opens in a new tab)