CVE-2026-100779: Vulnerability in Mozilla Firefox
Use-after-free in the XSLT component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
AI Analysis
Technical Summary
This vulnerability involves a use-after-free condition in the XSLT component of Mozilla Firefox, which could lead to memory safety issues. The Mozilla Foundation has fixed this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17. The advisory is part of a broader set of memory safety vulnerabilities addressed simultaneously. No active exploitation has been reported.
Potential Impact
The vulnerability poses a high impact risk due to its nature as a use-after-free bug, which can potentially lead to memory corruption and security breaches if exploited. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
A fix is available and users should upgrade to Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17 or later. Applying these official patches fully mitigates the vulnerability.
CVE-2026-100779: Vulnerability in Mozilla Firefox
Description
Use-after-free in the XSLT component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.
CVSS v3.1
Score 8.8high
Affected software
Mozilla
Firefox
pkg:github/mozilla/firefoxRun 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 XSLT component of Mozilla Firefox, which could lead to memory safety issues. The Mozilla Foundation has fixed this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17. The advisory is part of a broader set of memory safety vulnerabilities addressed simultaneously. No active exploitation has been reported.
Potential Impact
The vulnerability poses a high impact risk due to its nature as a use-after-free bug, which can potentially lead to memory corruption and security breaches if exploited. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
A fix is available and users should upgrade to Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, or Firefox ESR 140.17 or later. Applying these official patches fully mitigates the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:16:50.745Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-100/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-97/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-98/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-99/","vendor":"Mozilla"}]
Threat ID: 6abbb3eff7a7c5410664097c
Added to database: 09/29/2026, 12:49:51 UTC
Last enriched: 09/29/2026, 13:32:49 UTC
Last updated: 09/29/2026, 18:20:12 UTC
Views: 3
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