Firefox: Service Workers DOM Mitigation Bypass (CVE-2026-16407)
CVE-2026-16407 Published on July 21, 2026

Mitigation bypass in the DOM: Service Workers component
Mitigation bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

NVD

Vulnerability Analysis

CVE-2026-16407 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.

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

Weakness Types

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.

What is an Authorization Vulnerability?

The software does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

CVE-2026-16407 has been classified to as an Authorization vulnerability or weakness.


Products Associated with CVE-2026-16407

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Affected Versions

Mozilla Firefox: Mozilla Thunderbird: