CVE-2026-0877: mozjs52 · Mitigation Bypass
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.1 High : upgrade to 1:140.7.1+build1-0ubuntu0.22.04.1 soon.
Data as of 28 Oct 2026, 22:28 UTC
- Patch
- Available – fixed in 1:140.7.1+build1-0ubuntu0.22.04.1
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 Jan 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
Upgrade the Ubuntu thunderbird package to 1:140.7.1+build1-0ubuntu0.22.04.1.
Patches and advisories
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.
Description
Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 147, Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
References
- ubuntu.com/security/CVE-2026-0877 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-0877 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-01/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2026-03/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=1999257 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-01/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-02/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-03/ (opens in a new tab)
- ubuntu.com/security/notices/USN-7991-1 (opens in a new tab)