CVE-2026-100780: Vulnerability in Mozilla Firefox
Use-after-free in the DOM: Core & HTML 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
CVE-2026-100780 is a use-after-free vulnerability affecting the DOM: Core & HTML component in Mozilla Firefox. Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, potentially leading to memory corruption and security issues. Mozilla fixed this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17 as part of a broader security update addressing multiple high-impact vulnerabilities.
Potential Impact
The vulnerability is rated as high impact by Mozilla, indicating it could allow an attacker to cause memory corruption that may lead to arbitrary code execution or other serious security consequences if exploited. No known exploits in the wild have been reported at this time.
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 to these versions or later to mitigate the risk. Since this is not a cloud service, remediation depends on applying these updates. Patch status is confirmed by the vendor advisory.
CVE-2026-100780: Vulnerability in Mozilla Firefox
Description
Use-after-free in the DOM: Core & HTML 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
CVE-2026-100780 is a use-after-free vulnerability affecting the DOM: Core & HTML component in Mozilla Firefox. Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, potentially leading to memory corruption and security issues. Mozilla fixed this vulnerability in Firefox ESR 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17 as part of a broader security update addressing multiple high-impact vulnerabilities.
Potential Impact
The vulnerability is rated as high impact by Mozilla, indicating it could allow an attacker to cause memory corruption that may lead to arbitrary code execution or other serious security consequences if exploited. No known exploits in the wild have been reported at this time.
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 to these versions or later to mitigate the risk. Since this is not a cloud service, remediation depends on applying these updates. Patch status is confirmed by the vendor advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:16:53.413Z
- 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: 6abbb3eff7a7c5410664097d
Added to database: 09/29/2026, 12:49:51 UTC
Last enriched: 09/29/2026, 13:32:45 UTC
Last updated: 09/29/2026, 18:20:12 UTC
Views: 2
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