CVE-2026-74949: Vulnerability in Mozilla Firefox
Privilege escalation due to use-after-free in the Graphics: Canvas2D 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-2026-74949 is a use-after-free vulnerability in the Graphics: Canvas2D component of Mozilla Firefox that leads to privilege escalation. The flaw was reported by researcher r00tdaddy and is classified with high impact. Mozilla fixed this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. The vendor advisory confirms the fix and includes this vulnerability among multiple high-impact security issues resolved in these releases.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escalate privileges within the Firefox browser, potentially leading to execution of unauthorized actions or code with elevated rights. The impact is rated high by Mozilla, indicating significant security risk if left unpatched.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official patches.
CVE-2026-74949: Vulnerability in Mozilla Firefox
Description
Privilege escalation due to use-after-free in the Graphics: Canvas2D 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.
CVSS v3.1
Score 8.8high
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.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-74949 is a use-after-free vulnerability in the Graphics: Canvas2D component of Mozilla Firefox that leads to privilege escalation. The flaw was reported by researcher r00tdaddy and is classified with high impact. Mozilla fixed this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. The vendor advisory confirms the fix and includes this vulnerability among multiple high-impact security issues resolved in these releases.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escalate privileges within the Firefox browser, potentially leading to execution of unauthorized actions or code with elevated rights. The impact is rated high by Mozilla, indicating significant security risk if left unpatched.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154, Firefox ESR 140.14, and Firefox ESR 153.1. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official patches.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:57.441Z
- 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: 6a845504c6e8be03323673c5
Added to database: 08/18/2026, 12:50:12 UTC
Last enriched: 08/18/2026, 13:55:39 UTC
Last updated: 08/19/2026, 01:28:50 UTC
Views: 6
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