CVE-2026-109733: Vulnerability in Mozilla Firefox
Description
JIT miscompilation 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.
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
pkg:github/mozilla/firefox-esrRun 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
CVE-2026-109733 is a vulnerability involving JIT miscompilation in the JavaScript engine of Mozilla Firefox. The issue affects the JIT component and was resolved in Firefox 158, Firefox ESR 115.43, and Firefox ESR 153.5. The vendor has published advisories detailing the fix. There is no CVSS score available for this vulnerability.
Potential Impact
The vulnerability could potentially cause incorrect code execution due to JIT miscompilation, which might lead to unexpected behavior or security issues. However, no active exploitation has been reported, and the vendor has issued fixes to address the problem.
Mitigation Recommendations
Users and administrators should update Firefox to version 158 or later, or the corresponding ESR versions 115.43 or 153.5 to remediate this vulnerability. Applying these official fixes fully mitigates the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:29:39.388Z
- 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: 6ace2c482cdf04f65661d539
Added to database: 10/13/2026, 13:04:08 UTC
Last enriched: 10/13/2026, 13:49:21 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.