CVE-2025-11714: Mozilla Firefox · Out-of-bounds Write
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in– |
AI-suggested
Official patches are available and have been released by Mozilla in Firefox 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4. Users and administrators should update to these fixed versions to remediate the vulnerabilities. Since this is not a cloud service, remediation depends on applying these updates. Patch status is confirmed by Mozilla advisories mfsa2025-81 and mfsa2025-82.
Description
Memory safety bugs present in Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. 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 144, Firefox ESR 115.29, Firefox ESR 140.4, Thunderbird 144, and Thunderbird 140.4.
References
- bugzilla.mozilla.org/buglist.cgi?bug_id=1973699%2C1989945%2C1990970%2C1991040%2C1992113 (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)
- lists.debian.org/debian-lts-announce/2025/10/msg00031.html (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/10/msg00015.html (opens in a new tab)