CVE-2025-11711: There was a way to change the value of JavaScript Object properties that were supposed to be
Source GCVE Database
Not known to be exploited · CVSS 6.5 Medium · fixed in 144 : update affected systems when convenient.
Data as of 29 Oct 2026, 23:57 UTC
- Patch
- Available – fixed in 144, 140.4, 115.29
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 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
This vulnerability has been fixed in Firefox 144, Firefox ESR 115.29 and 140.4, and Thunderbird 144 and 140.4. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required as the vendor advisory confirms an official fix is available.
Description
CVE-2025-11711 is a vulnerability in Firefox and Thunderbird where some JavaScript Object properties that were intended to be non-writeable could be modified. This issue affects Firefox versions prior to 144 and Firefox ESR versions prior to 115.29 and 140.4, as well as Thunderbird versions prior to 144 and 140.4. The vulnerability was addressed in Firefox 144 and corresponding ESR and Thunderbird releases.
References
- nvd.nist.gov/vuln/detail/CVE-2025-11711 (opens in a new tab)
- bugzilla.mozilla.org/show_bug.cgi?id=1989978 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00015.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00031.html (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-81 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-82 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-83 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-84 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-85 (opens in a new tab)