CVE-2026-8952: 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 31% 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 fixed this vulnerability in Firefox 151 and Thunderbird 151. Users and administrators should update to these versions or later to remediate the issue. Since this is not a cloud service, patching the client software is required. No additional mitigation steps are indicated by the vendor advisory.
Description
CVE-2026-8952 is a privilege escalation vulnerability in the Application Update component of Mozilla Firefox and Thunderbird. This vulnerability has been fixed in Firefox 151 and Thunderbird 151. The issue was reported by Tomoya Nakanishi and is classified with moderate impact by Mozilla. The vulnerability allows an attacker to escalate privileges within the affected application. Mozilla has released security advisories confirming the fix in the specified versions. No known exploits in the wild have been reported. The CVSS score for this vulnerability is 8.8, indicating a high severity level overall, but Mozilla rates the impact of this specific issue as moderate.