CVE-2026-6763: Mozilla Firefox · CWE-693
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium · patch available : update Mozilla Firefox when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 21 Apr 2026
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 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
This vulnerability has been fixed in Mozilla Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. Users and administrators should update to these versions or later to remediate the issue. Since the vendor advisory confirms the fix, no additional mitigation steps are required beyond applying the official update.
Description
Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
References
- bugzilla.mozilla.org/show_bug.cgi?id=2021666 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-30/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-32/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-33/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-34/ (opens in a new tab)