CVE-2026-6761: Mozilla Firefox · Improper Privilege Management
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · patch available : patch Mozilla Firefox soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% 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:R/S:U/C:H/I:H/A:HExploitation 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
Mozilla has fixed this vulnerability in 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 vulnerability. Since this is not a cloud service, patching the client software is required. There are no vendor advisories indicating that no action is required or that the issue is already mitigated without patching.
Description
Privilege escalation in the Networking 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=2017857 (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)