CVE-2025-5268: Memory Safety Bugs Present
Source GCVE Database
Not known to be exploited · CVSS 8.1 High · fixed in 139 : patch affected systems soon.
Data as of 30 Oct 2026, 01:42 UTC
- Patch
- Available – fixed in 139, 128.11
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
Weaponized: 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 29 Oct 2026.
What to do
AI-suggested
These vulnerabilities have been fixed in Firefox 139, Thunderbird 139, Firefox ESR 128.11, and Thunderbird 128.11. Users and administrators should update to these versions or later to mitigate the risk. No additional mitigation steps are required beyond applying the official updates.
Description
Memory safety bugs were identified in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. These bugs showed evidence of memory corruption and could potentially be exploited to execute arbitrary code. The vulnerabilities have been fixed in Firefox 139, Thunderbird 139, Firefox ESR 128.11, and Thunderbird 128.11. The CVSS score for this issue is 6.5, indicating a medium severity level.
References
- nvd.nist.gov/vuln/detail/CVE-2025-5268 (opens in a new tab)
- bugzilla.mozilla.org/buglist.cgi?bug_id=1950136%2C1958121%2C1960499%2C1962634 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00043.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00046.html (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)
- mozilla.org/security/advisories/mfsa2025-45 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-46 (opens in a new tab)