CVE-2026-74974: Vulnerability in Mozilla Firefox
Same-origin policy bypass in the Graphics: ImageLib 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-2026-74974 is a vulnerability in Mozilla Firefox's Graphics: ImageLib component that enables bypassing the same-origin policy. The same-origin policy is a fundamental browser security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. This vulnerability was addressed and fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. The Mozilla advisories indicate the impact as moderate and list this issue among several other high and moderate severity vulnerabilities fixed in these releases.
Potential Impact
The vulnerability allows bypassing the same-origin policy, potentially enabling unauthorized access to resources or data across different origins within the browser context. This can lead to privacy violations or unauthorized data access. The vendor rates the impact as moderate. There are no known exploits in the wild reported at this time.
Mitigation Recommendations
A fix for this vulnerability is available. 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 to remediate this issue. Applying these official updates fully mitigates the vulnerability.
CVE-2026-74974: Vulnerability in Mozilla Firefox
Description
Same-origin policy bypass in the Graphics: ImageLib 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 5.4medium
Affected software
pkg:github/mozilla/firefoxRun 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-2026-74974 is a vulnerability in Mozilla Firefox's Graphics: ImageLib component that enables bypassing the same-origin policy. The same-origin policy is a fundamental browser security mechanism that restricts how documents or scripts loaded from one origin can interact with resources from another origin. This vulnerability was addressed and fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, and Firefox ESR 153.1. The Mozilla advisories indicate the impact as moderate and list this issue among several other high and moderate severity vulnerabilities fixed in these releases.
Potential Impact
The vulnerability allows bypassing the same-origin policy, potentially enabling unauthorized access to resources or data across different origins within the browser context. This can lead to privacy violations or unauthorized data access. The vendor rates the impact as moderate. There are no known exploits in the wild reported at this time.
Mitigation Recommendations
A fix for this vulnerability is available. 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 to remediate this issue. Applying these official updates fully mitigates the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-08-17T11:58:52.693Z
- 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/mfsa2026-75/","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: 6a84550bc6e8be03323676b0
Added to database: 08/18/2026, 12:50:19 UTC
Last enriched: 08/18/2026, 13:25:54 UTC
Last updated: 08/19/2026, 01:21:00 UTC
Views: 7
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