rust-ammonia up to 3.3.1/4.0.1/4.1.2 cross site scripting

Summaryinfo

A vulnerability labeled as problematic has been found in rust-ammonia ammonia up to 3.3.1/4.0.1/4.1.2. This affects an unknown function. The manipulation results in cross site scripting. This vulnerability is known as CVE-2026-63430. It is possible to launch the attack remotely. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in rust-ammonia ammonia up to 3.3.1/4.0.1/4.1.2. Affected is an unknown part. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

ammonia is a Rust library for repairing and securing untrusted HTML. Prior to 3.3.2, 4.0.2, and 4.1.3, applications that explicitly allow the math tag, annotation-xml, and at least one raw-text HTML element while disallowing the encoding attribute can permit mutation cross-site scripting. ammonia does not correctly implement annotation-xml's encoding-dependent MathML integration-point behavior after attribute filtering removes encoding, so the sanitizer validates a descendant under one namespace interpretation while the browser reparses the output under another. An attacker can use that namespace transition and an allowed raw-text HTML element to execute JavaScript when a user renders the sanitized output. The required tags are not enabled by default, so applications that do not explicitly allow them are not affected. This issue is fixed in versions 3.3.2, 4.0.2, and 4.1.3.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-63430 since 07/16/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 3.3.2, 4.0.2 or 4.1.3 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• rust-ammonia

Name

• ammonia

Version

• 3.3.0
• 3.3.1
• 4.0.0
• 4.0.1
• 4.1.0
• 4.1.1
• 4.1.2

Website

• Product: https://github.com/rust-ammonia/ammonia/

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Once again VulDB remains the best source for vulnerability data.

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