CVE-2025-5268: Mozjs52 · Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and
Affects mozjs52Source GCVE Database
Not known to be exploited · CVSS 8.1 High : upgrade to 1:128.12.0+build1-0ubuntu0.22.04.1 soon.
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:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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
Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 139, Firefox ESR 128.11, Thunderbird 139, and Thunderbird 128.11.
References
- ubuntu.com/security/CVE-2025-5268 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-5268 (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2025-42/ (opens in a new tab)
- mozilla.org/en-US/security/advisories/mfsa2025-44/ (opens in a new tab)
- bugzilla.mozilla.org/buglist.cgi?bug_id=1950136%2C1958121%2C1960499%2C1962634 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-42/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-44/ (opens in a new tab)
- ubuntu.com/security/notices/USN-7663-1 (opens in a new tab)