CVE-2026-16358: Vulnerability in Mozilla Firefox
Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
AI Analysis
Technical Summary
CVE-2026-16358 is a site isolation issue affecting the Graphics: WebRender component in Mozilla Firefox. Site isolation vulnerabilities can allow processes or content to access data or resources they should be isolated from. Mozilla fixed this vulnerability in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. The vendor advisories confirm the fix and classify the impact as moderate. No active exploitation has been reported. The vulnerability is part of a broader set of security fixes released by Mozilla on July 21, 2026.
Potential Impact
The vulnerability could potentially allow bypass of site isolation protections within the WebRender graphics component, which might lead to unauthorized access to data or resources across site boundaries. However, the impact is assessed as moderate by Mozilla, and no known exploits in the wild have been reported.
Mitigation Recommendations
Users and administrators should update Mozilla Firefox to version 153 or later, or Firefox ESR to version 115.38 or later, where this vulnerability has been fixed. The vendor has released official patches addressing this issue. Applying these updates fully mitigates the vulnerability.
CVE-2026-16358: Vulnerability in Mozilla Firefox
Description
Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13.
Affected software
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-16358 is a site isolation issue affecting the Graphics: WebRender component in Mozilla Firefox. Site isolation vulnerabilities can allow processes or content to access data or resources they should be isolated from. Mozilla fixed this vulnerability in Firefox 153, Firefox ESR 115.38, and Firefox ESR 140.13. The vendor advisories confirm the fix and classify the impact as moderate. No active exploitation has been reported. The vulnerability is part of a broader set of security fixes released by Mozilla on July 21, 2026.
Potential Impact
The vulnerability could potentially allow bypass of site isolation protections within the WebRender graphics component, which might lead to unauthorized access to data or resources across site boundaries. However, the impact is assessed as moderate by Mozilla, and no known exploits in the wild have been reported.
Mitigation Recommendations
Users and administrators should update Mozilla Firefox to version 153 or later, or Firefox ESR to version 115.38 or later, where this vulnerability has been fixed. The vendor has released official patches addressing this issue. Applying these updates fully mitigates the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-07-20T21:56:05.445Z
- Cvss Version
- null
- State
- PUBLISHED
- Remediation Level
- null
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-68/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-69/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-70/","vendor":"Mozilla"}]
Threat ID: 6a5f6cb92a4a8d5989262438
Added to database: 07/21/2026, 12:57:29 UTC
Last enriched: 07/21/2026, 13:43:07 UTC
Last updated: 07/21/2026, 21:18:36 UTC
Views: 5
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