CVE-2026-109772: Mozjs52 · Same-origin policy bypass in the DevTools component
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 9.1 Critical.
Data as of 28 Oct 2026, 01:30 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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
A fix for this vulnerability is available in Firefox 158 and Thunderbird 158. Users and administrators should upgrade to these versions or later to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-109772 is a critical vulnerability in the mozjs52 DevTools component that allows bypass of the same-origin policy. This flaw was addressed and fixed in Firefox 158 and Thunderbird 158. The vulnerability has a high CVSS score of 9.1, indicating it can lead to high confidentiality and integrity impact without user interaction or privileges. No known exploits in the wild have been reported. Users should upgrade to Firefox 158 or later to mitigate this issue.
References
- ubuntu.com/security/CVE-2026-109772 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-109772 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-106/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=2066063 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-106/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-109/ (opens in a new tab)