CVE-2026-92017: Mozilla Firefox · Improper Privilege Management
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 15% 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 15 Sep 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 by Mozilla. Users and administrators should update affected products to Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, or Thunderbird 153.3 or later versions. No additional mitigation actions are required once the update is applied.
Description
CVE-2026-92017 is a high-severity privilege escalation vulnerability in the DOM Service Workers component of Mozilla Firefox and Thunderbird. This vulnerability allows an attacker to escalate privileges within the affected applications. The issue has been fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.
References
- bugzilla.mozilla.org/show_bug.cgi?id=2061777 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-90/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-91/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-92/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-93/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-95/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-94/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-96/ (opens in a new tab)