CVE-2026-109729: Vulnerability in Mozilla Firefox
Description
Use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 158, Firefox ESR 115.43, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
CVSS v3.1
Score 5.4medium
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a use-after-free condition within the Just-In-Time (JIT) compilation component of the JavaScript engine in Mozilla Firefox. Such a flaw could potentially lead to memory corruption. Mozilla has released fixes in Firefox 158, Firefox ESR 115.43, and Firefox ESR 153.5 to remediate this issue.
Potential Impact
The vulnerability could allow an attacker to cause memory corruption, which might lead to arbitrary code execution or browser crashes if exploited. However, no active exploitation has been reported.
Mitigation Recommendations
Users should update to Firefox 158, Firefox ESR 115.43, or Firefox ESR 153.5 or later versions where this vulnerability has been fixed. Applying these official updates fully mitigates the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:29:35.614Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-107/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","vendor":"Mozilla"}]
Threat ID: 6ace2c462cdf04f65661d525
Added to database: 10/13/2026, 13:04:06 UTC
Last enriched: 10/13/2026, 13:49:35 UTC
Last updated: 10/13/2026, 18:57:33 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.