CVE-2026-74946: Vulnerability in Mozilla Firefox
Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
AI Analysis
Technical Summary
CVE-2026-74946 is a privilege escalation vulnerability due to incorrect boundary conditions in the Graphics: CanvasWebGL component of Mozilla Firefox. This vulnerability was reported by locust1b and is classified with high impact. It was fixed in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. The Mozilla advisories indicate this is one of several high-impact security issues resolved in these releases. No CVSS score is provided. The vendor advisories confirm the fix availability and recommend updating to the specified versions.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escalate privileges within the Firefox browser, potentially leading to unauthorized actions or code execution in the browser context. The impact is rated high by Mozilla. There are no known exploits in the wild at this time.
Mitigation Recommendations
Users and administrators should update Mozilla Firefox to version 154 or later, or Firefox ESR to versions 115.39, 140.14, or 153.1 or later, where this vulnerability is fixed. Applying these official updates fully mitigates the vulnerability. No additional mitigation steps are indicated by the vendor.
CVE-2026-74946: Vulnerability in Mozilla Firefox
Description
Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, 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-2026-74946 is a privilege escalation vulnerability due to incorrect boundary conditions in the Graphics: CanvasWebGL component of Mozilla Firefox. This vulnerability was reported by locust1b and is classified with high impact. It was fixed in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. The Mozilla advisories indicate this is one of several high-impact security issues resolved in these releases. No CVSS score is provided. The vendor advisories confirm the fix availability and recommend updating to the specified versions.
Potential Impact
Successful exploitation of this vulnerability could allow an attacker to escalate privileges within the Firefox browser, potentially leading to unauthorized actions or code execution in the browser context. The impact is rated high by Mozilla. There are no known exploits in the wild at this time.
Mitigation Recommendations
Users and administrators should update Mozilla Firefox to version 154 or later, or Firefox ESR to versions 115.39, 140.14, or 153.1 or later, where this vulnerability is fixed. Applying these official updates fully mitigates the vulnerability. No additional mitigation steps are indicated by the vendor.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:51.255Z
- 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/mfsa2026-75/","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: 6a845504c6e8be03323673bf
Added to database: 08/18/2026, 12:50:12 UTC
Last enriched: 08/18/2026, 13:56:07 UTC
Last updated: 08/19/2026, 01:31:46 UTC
Views: 5
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