CVE-2025-4087: Mozjs52 · A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 4.8 Medium : upgrade to 1:128.12.0+build1-0ubuntu0.22.04.1 when convenient.
Data as of 28 Oct 2026, 22:28 UTC
- Patch
- Available – fixed in 1:128.12.0+build1-0ubuntu0.22.04.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Apr 2025
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 1:128.12.0+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
A vulnerability was identified in Thunderbird where XPath parsing could trigger undefined behavior due to missing null checks during attribute access. This could lead to out-of-bounds read access and potentially, memory corruption. This vulnerability was fixed in Firefox 138, Firefox ESR 128.10, Thunderbird 138, and Thunderbird 128.10.
References
- ubuntu.com/security/CVE-2025-4087 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-4087 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2025-28/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2025-29/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2025-32/ (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=1952465 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-28/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-29/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-31/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-32/ (opens in a new tab)
- ubuntu.com/security/notices/USN-7663-1 (opens in a new tab)