CVE-2026-109766: Mozjs52 · Mitigation bypass in the Enterprise Policies component
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.1 High.
Data as of 28 Oct 2026, 23:44 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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
This vulnerability has been fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5. Users and administrators should update to these or later versions to remediate the issue. No additional mitigations are required beyond applying the official fixes.
Description
CVE-2026-109766 is a high-severity mitigation bypass vulnerability in the Enterprise Policies component of mozjs52. This flaw allows an attacker to bypass security mitigations implemented via enterprise policies. The issue was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
References
- ubuntu.com/security/CVE-2026-109766 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-109766 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-106/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-108/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-109/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=2074406 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-106/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-108/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-109/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-110/ (opens in a new tab)