CVE-2025-9184: Mozilla Firefox · Memory Buffer Overflow
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.1 High.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 19 Aug 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 addressing these vulnerabilities have been released by Mozilla in Firefox 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird ESR 140.2. Users and administrators should apply these updates promptly to mitigate the risk. Since the vulnerabilities are fixed in these versions, no additional mitigation steps are required beyond updating to the fixed versions.
Description
Memory safety bugs present in Firefox ESR 140.1, Thunderbird ESR 140.1, Firefox 141 and Thunderbird 141. 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 142, Firefox ESR 140.2, Thunderbird 142, and Thunderbird 140.2.
References
- bugzilla.mozilla.org/buglist.cgi?bug_id=1929482%2C1976376%2C1979163%2C1979955 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-64/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-67/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-70/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2025-72/ (opens in a new tab)