CVE-2026-74934: Vulnerability in Mozilla Firefox
CVE-2026-74934 is a high-severity vulnerability in Mozilla Firefox affecting the Graphics: CanvasWebGL component related to site isolation. This issue was fixed in Firefox 154 and corresponding ESR versions 115.39, 140.14, and 153.1. The vulnerability could lead to significant confidentiality, integrity, and availability impacts. No known exploits in the wild have been reported. Mozilla has released official fixes for this vulnerability.
AI Analysis
Technical Summary
CVE-2026-74934 is a site isolation vulnerability in the Graphics: CanvasWebGL component of Mozilla Firefox. It was identified and reported by satyamasd and is classified with a CVSS 3.1 score of 7.5 (high severity) indicating network attack vector, high complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability. The issue was addressed and fixed in Firefox 154, Firefox ESR 115.39, 140.14, and 153.1. The vendor advisories confirm the fix and provide detailed references to the underlying bugs.
Potential Impact
The vulnerability allows potential compromise of site isolation in the CanvasWebGL graphics component, which could lead to unauthorized information disclosure, privilege escalation, or other security breaches affecting confidentiality, integrity, and availability of the browser environment. The CVSS score of 7.5 reflects a high impact if exploited. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. Users and administrators should update to these fixed versions or later to remediate the issue. No additional mitigation actions are required beyond applying these official updates.
CVE-2026-74934: Vulnerability in Mozilla Firefox
Description
CVE-2026-74934 is a high-severity vulnerability in Mozilla Firefox affecting the Graphics: CanvasWebGL component related to site isolation. This issue was fixed in Firefox 154 and corresponding ESR versions 115.39, 140.14, and 153.1. The vulnerability could lead to significant confidentiality, integrity, and availability impacts. No known exploits in the wild have been reported. Mozilla has released official fixes for this vulnerability.
CVSS v3.1
Score 7.5high
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
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-2026-74934 is a site isolation vulnerability in the Graphics: CanvasWebGL component of Mozilla Firefox. It was identified and reported by satyamasd and is classified with a CVSS 3.1 score of 7.5 (high severity) indicating network attack vector, high complexity, no privileges required, user interaction required, and high impact on confidentiality, integrity, and availability. The issue was addressed and fixed in Firefox 154, Firefox ESR 115.39, 140.14, and 153.1. The vendor advisories confirm the fix and provide detailed references to the underlying bugs.
Potential Impact
The vulnerability allows potential compromise of site isolation in the CanvasWebGL graphics component, which could lead to unauthorized information disclosure, privilege escalation, or other security breaches affecting confidentiality, integrity, and availability of the browser environment. The CVSS score of 7.5 reflects a high impact if exploited. However, there are no known active exploits in the wild at this time.
Mitigation Recommendations
Mozilla has released official fixes for this vulnerability in Firefox 154 and Firefox ESR versions 115.39, 140.14, and 153.1. Users and administrators should update to these fixed versions or later to remediate the issue. No additional mitigation actions are required beyond applying these official updates.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:57:25.126Z
- State
- PUBLISHED
- 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: 6a845502c6e8be0332367397
Added to database: 08/18/2026, 12:50:10 UTC
Last enriched: 09/11/2026, 22:04:11 UTC
Last updated: 10/03/2026, 02:46:06 UTC
Views: 93
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