CVE-2026-109739: Vulnerability in Mozilla Firefox
Description
Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves privilege escalation within the WebExtensions component of Mozilla Firefox. It was publicly disclosed and fixed in Firefox 158. No CVSS score or detailed technical exploitation information is available from the provided data.
Potential Impact
Successful exploitation could allow an attacker to escalate privileges within the Firefox browser environment. No information about active exploitation or broader impact is available.
Mitigation Recommendations
Users should update Firefox to version 158 or later to remediate this vulnerability. The vendor advisory confirms the issue is fixed in Firefox 158.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:29:45.310Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","vendor":"Mozilla"}]
Threat ID: 6ace2c482cdf04f65661d53f
Added to database: 10/13/2026, 13:04:08 UTC
Last enriched: 10/13/2026, 13:48:59 UTC
Last updated: 10/14/2026, 04:19:18 UTC
Views: 2
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.