CVE-2026-8957: 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
- 0.3% chance of exploitation in 30 days – higher than 32% 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 19 May 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 released official fixes for this vulnerability in Firefox 151 and Firefox ESR 140.11. Users and administrators should apply these updates promptly to remediate the issue. Since the vulnerability is fixed in these versions, no additional mitigation steps are required beyond updating to the patched releases.
Description
CVE-2026-8957 is a privilege escalation vulnerability in the Enterprise Policies component of Mozilla Firefox. It was fixed in Firefox 151 and Firefox ESR 140.11. The vulnerability has a high severity with a CVSS score of 8.8. Mozilla has officially addressed this issue in their security advisories dated May 19, 2026. No known exploits in the wild have been reported. Users should update to the fixed versions to mitigate this vulnerability.
References
- bugzilla.mozilla.org/show_bug.cgi?id=2033850 (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-46/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-48/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-50/ (opens in a new tab)
- mozilla.org/security/advisories/mfsa2026-51/ (opens in a new tab)