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VulnerabilityPublished Updated

CVE-2026-109726: Mozjs52 · Use-after-free in the SVG component

Affects mozjs52Source GCVE Database

0
Authoritative record:CVE-2026-109726· Medium 5.4

Not known to be exploited · CVSS 5.4 Medium.

Data as of 29 Oct 2026, 00:30 UTC

CVSS 3.1 base score
5.4Medium
How severe the flaw is on the 0–10 CVSS scale.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 13 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
Ubuntu 24.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=nobleOther threatsAffected
  • =102.15.1-1
  • =102.15.1-3ubuntu2
Fixed in–
Ubuntu 24.04 LTSmozjs115pkg:deb/ubuntu/mozjs115?arch=source&distro=nobleOther threatsAffected
  • 115.3.0-0ubuntu1 – 115.10.0-1
9 affected builds
Fixed in–
Ubuntu 22.04 LTSmozjs102pkg:deb/ubuntu/mozjs102?arch=source&distro=jammyOther threatsAffected
  • 102.11.0-0ubuntu0.22.04.1 – 102.15.1-0ubuntu0.22.04.1
4 affected builds
Fixed in–
Ubuntu 22.04 LTSmozjs78pkg:deb/ubuntu/mozjs78?arch=source&distro=jammyOther threatsAffected
  • =78.13.0-1
  • =78.15.0-2
  • =78.15.0-4ubuntu1
Fixed in–
Ubuntu 22.04 LTSmozjs91pkg:deb/ubuntu/mozjs91?arch=source&distro=jammyOther threatsAffected
  • 91.5.1-0ubuntu1 – 91.10.0-0ubuntu1
5 affected builds
Fixed in–
Ubuntu 22.04 LTSthunderbirdpkg:deb/ubuntu/thunderbird?arch=source&distro=jammyOther threatsAffected
  • 1:91.1.2+build1-0ubuntu1 – 1:140.7.1+build1-0ubuntu0.22.04.1
39 affected builds
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 is available and has been released by Mozilla in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5. Users and administrators should upgrade to these or later versions to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.

Description

CVE-2026-109726 is a use-after-free vulnerability in the SVG component of the mozjs52 JavaScript engine used by Firefox and Thunderbird. This flaw allows for potential memory corruption. It was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5. The vulnerability has a medium severity rating with a CVSS score of 5.4 and does not have known exploits in the wild.

References

Community reviews

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