CVE-2026-100767: Vulnerability in Mozilla Firefox
Use-after-free in the Networking: Cache 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 Networking: Cache component of Mozilla Firefox. Use-after-free bugs occur when a program continues to use memory after it has been freed, potentially leading to memory corruption and security issues. Mozilla 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 high-impact security fixes released by Mozilla on September 29, 2026.
Potential Impact
The use-after-free vulnerability in the Networking: Cache component could allow an attacker to cause memory corruption, which may lead to arbitrary code execution or browser instability. Given the high impact rating assigned by Mozilla, exploitation could compromise the security and stability of affected Firefox installations. However, no active exploitation in the wild has been reported.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17. Users and administrators should update affected Firefox installations to these versions or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official patches.
CVE-2026-100767: Vulnerability in Mozilla Firefox
Description
Use-after-free in the Networking: Cache 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 Networking: Cache component of Mozilla Firefox. Use-after-free bugs occur when a program continues to use memory after it has been freed, potentially leading to memory corruption and security issues. Mozilla 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 high-impact security fixes released by Mozilla on September 29, 2026.
Potential Impact
The use-after-free vulnerability in the Networking: Cache component could allow an attacker to cause memory corruption, which may lead to arbitrary code execution or browser instability. Given the high impact rating assigned by Mozilla, exploitation could compromise the security and stability of affected Firefox installations. However, no active exploitation in the wild has been reported.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17. Users and administrators should update affected Firefox installations to these versions or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:15:23.891Z
- 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: 6abbb3edf7a7c5410664096b
Added to database: 09/29/2026, 12:49:49 UTC
Last enriched: 09/29/2026, 13:33:34 UTC
Last updated: 09/29/2026, 18:20:12 UTC
Views: 2
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