Mitigation Bypass in Firefox DOM Networking (before 153/140.13)
CVE-2026-16383 Published on July 21, 2026
Mitigation bypass in the DOM: Networking component
Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Vulnerability Analysis
CVE-2026-16383 can be exploited 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.
Weakness Type
Protection Mechanism Failure
The product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product. This weakness covers three distinct situations. A "missing" protection mechanism occurs when the application does not define any mechanism against a certain class of attack. An "insufficient" protection mechanism might provide some defenses - for example, against the most common attacks - but it does not protect against everything that is intended. Finally, an "ignored" mechanism occurs when a mechanism is available and in active use within the product, but the developer has not applied it in some code path.
Products Associated with CVE-2026-16383
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Affected Versions
Mozilla Firefox:- Version 140.13, <= 140.* is unaffected.
- Version 153, <= * is unaffected.
- Version 140.13, <= 140.* is unaffected.
- Version 153, <= * is unaffected.