CVE-2026-100831: Vulnerability in Mozilla Firefox
Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
AI Analysis
Technical Summary
This vulnerability involves a use-after-free condition in the DOM UI Events & Focus Handling component of Mozilla Firefox. Use-after-free bugs occur when memory is accessed after it has been freed, potentially leading to memory corruption and security issues. Mozilla fixed this vulnerability in Firefox ESR 153.4 and Firefox 157 as part of a security advisory addressing multiple high-impact vulnerabilities. There are no reports of active exploitation in the wild for this specific CVE.
Potential Impact
The vulnerability has a high impact classification as it involves use-after-free memory corruption, which can potentially be exploited to cause crashes or execute arbitrary code. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
A fix is available and has been officially released by Mozilla. Users and administrators should update to Firefox ESR 153.4 or later, or Firefox 157 or later, to remediate this vulnerability. No additional mitigation steps are required beyond applying the official update.
CVE-2026-100831: Vulnerability in Mozilla Firefox
Description
Use-after-free in the DOM: UI Events & Focus Handling component. This vulnerability was fixed in Firefox ESR 153.4 and Firefox 157.
CVSS v3.1
Score 8.8high
Affected software
Mozilla
Firefox
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a use-after-free condition in the DOM UI Events & Focus Handling component of Mozilla Firefox. Use-after-free bugs occur when memory is accessed after it has been freed, potentially leading to memory corruption and security issues. Mozilla fixed this vulnerability in Firefox ESR 153.4 and Firefox 157 as part of a security advisory addressing multiple high-impact vulnerabilities. There are no reports of active exploitation in the wild for this specific CVE.
Potential Impact
The vulnerability has a high impact classification as it involves use-after-free memory corruption, which can potentially be exploited to cause crashes or execute arbitrary code. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
A fix is available and has been officially released by Mozilla. Users and administrators should update to Firefox ESR 153.4 or later, or Firefox 157 or later, to remediate this vulnerability. No additional mitigation steps are required beyond applying the official update.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-09-26T19:19:03.382Z
- 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"}]
Threat ID: 6abbb3f9f7a7c541066409ce
Added to database: 09/29/2026, 12:50:01 UTC
Last enriched: 09/29/2026, 13:02:49 UTC
Last updated: 09/29/2026, 18:20:13 UTC
Views: 8
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