CVE-2026-16358: FireFox WebRender Site Isolation Fix 153
CVE-2026-16358 Published on July 21, 2026

Site isolation issue in the Graphics: WebRender component
Site isolation issue in the Graphics: WebRender component. This vulnerability was fixed in Firefox 153, Firefox ESR 115.38, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

NVD

Vulnerability Analysis

CVE-2026-16358 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Origin Validation Error

The software does not properly verify that the source of data or communication is valid.


Products Associated with CVE-2026-16358

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Mozilla Firefox
 
Mozilla Thunderbird
 

Affected Versions

Mozilla Firefox: Mozilla Thunderbird: