CVE-2026-74934
Undergoing Analysis Undergoing Analysis - In Progress

Graphics: CanvasWebGL Site Isolation Flaw in Firefox

Publication date: 2026-08-18

Last updated on: 2026-08-18

Assigner: Mozilla Corporation

Description
Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1.

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Meta Information

Published
2026-08-18
Last Modified
2026-08-18
Generated
2026-08-18
AI Q&A
2026-08-18
EPSS Evaluated
N/A
NVD
CVE-2026-74934
EUVD
EUVD-2026-60743

Affected Vendors & Products

Showing 8 associated CPEs
Vendor Product Version / Range
mozilla firefox From 154 (inc)
mozilla firefox_esr From 115.39 (inc)
mozilla firefox_esr From 140.14 (inc)
mozilla firefox_esr From 153.1 (inc)
mozilla firefox to 154 (inc)
mozilla firefox_esr to 115.39 (inc)
mozilla firefox_esr to 140.14 (inc)
mozilla firefox_esr to 153.1 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a site isolation issue in Firefox's Graphics: CanvasWebGL component. Site isolation is a security feature that separates different websites into different processes to prevent data leaks between them. A flaw in CanvasWebGL could allow malicious websites to access data from other sites.

Detection Guidance

To detect this vulnerability, check the installed version of Firefox or Firefox ESR on your system. Compare it against the fixed versions: Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, or Firefox ESR 153.1. Use commands like 'firefox --version' or 'apt show firefox' depending on your OS.

Impact Analysis

If exploited, this vulnerability could allow an attacker to access sensitive data from other websites you have open in different tabs or windows. This might include personal information, login credentials, or other private data.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or other standards as it is a site isolation issue in Firefox's Graphics: CanvasWebGL component. No evidence suggests data exposure or privacy violations that would impact regulatory compliance.

Mitigation Strategies

Immediately update Firefox to version 154 or Firefox ESR to versions 115.39, 140.14, or 153.1. If automatic updates are disabled, manually download and install the latest version from Mozilla's official website.

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