CVE-2026-74944: Vulnerability in Mozilla Firefox
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
AI Analysis
Technical Summary
CVE-2026-74944 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 a pointer after the memory it points to has been freed, potentially leading to memory corruption and security issues. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1 as part of a broader security update addressing multiple high-impact bugs. The fix was officially released by Mozilla in their security advisories MFSA 2026-74 and MFSA 2026-76 on August 18, 2026.
Potential Impact
The vulnerability has a high impact rating due to the risk of memory corruption caused by use-after-free in a core browser component. Such vulnerabilities can potentially be exploited to execute arbitrary code or cause browser crashes, although no known exploits in the wild have been reported. The fix mitigates these risks by correcting the memory management flaw in the affected Firefox versions.
Mitigation Recommendations
A fix for CVE-2026-74944 is available and has been officially released by Mozilla. Users and administrators should update to Firefox 154, Firefox ESR 140.14, or Firefox ESR 153.1 or later to remediate this vulnerability. No additional mitigation actions are required beyond applying the official update.
CVE-2026-74944: Vulnerability in Mozilla Firefox
Description
Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
Affected software
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-2026-74944 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 a pointer after the memory it points to has been freed, potentially leading to memory corruption and security issues. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1 as part of a broader security update addressing multiple high-impact bugs. The fix was officially released by Mozilla in their security advisories MFSA 2026-74 and MFSA 2026-76 on August 18, 2026.
Potential Impact
The vulnerability has a high impact rating due to the risk of memory corruption caused by use-after-free in a core browser component. Such vulnerabilities can potentially be exploited to execute arbitrary code or cause browser crashes, although no known exploits in the wild have been reported. The fix mitigates these risks by correcting the memory management flaw in the affected Firefox versions.
Mitigation Recommendations
A fix for CVE-2026-74944 is available and has been officially released by Mozilla. Users and administrators should update to Firefox 154, Firefox ESR 140.14, or Firefox ESR 153.1 or later to remediate this vulnerability. No additional mitigation actions are required beyond applying the official update.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:46.693Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-74/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-76/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-77/","vendor":"Mozilla"}]
Threat ID: 6a845504c6e8be03323673bb
Added to database: 08/18/2026, 12:50:12 UTC
Last enriched: 08/18/2026, 13:56:27 UTC
Last updated: 08/19/2026, 02:32:41 UTC
Views: 6
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.