CVE-2026-109707: Vulnerability in Mozilla Firefox
Description
Sandbox escape due to use-after-free in the Networking component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
CVSS v3.1
Score 9.6critical
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.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a use-after-free condition in the Networking component of Mozilla Firefox, which could allow an attacker to escape the browser's sandbox. The issue was resolved by Mozilla in Firefox 158 and Firefox ESR 153.5. The vendor has published security advisories detailing the fix.
Potential Impact
Successful exploitation could allow an attacker to escape the sandbox environment, potentially leading to execution of arbitrary code outside the browser's restricted environment. However, no active exploitation has been reported.
Mitigation Recommendations
Users should update to Firefox 158 or later, or Firefox ESR 153.5 or later, where this vulnerability has been fixed. Applying these official updates fully mitigates the risk.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:29:16.501Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","vendor":"Mozilla"}]
Threat ID: 6ace2c402cdf04f65661caf4
Added to database: 10/13/2026, 13:04:00 UTC
Last enriched: 10/13/2026, 14:19:40 UTC
Last updated: 10/13/2026, 18:57:33 UTC
Views: 3
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.