CVE-2026-63430

Description

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.

References

https://rustsec.org/advisories/RUSTSEC-2026-0193.html

https://ivan09999.github.io/ammonia-mxss

https://github.com/rust-ammonia/ammonia/security/advisories/GHSA-9jh8-v38h-cvhr

https://github.com/rust-ammonia/ammonia/releases/tag/v4.1.3

https://github.com/rust-ammonia/ammonia/releases/tag/v4.0.2

https://github.com/rust-ammonia/ammonia/releases/tag/v3.3.2

https://github.com/rust-ammonia/ammonia/pull/245

https://github.com/rust-ammonia/ammonia/pull/244

https://github.com/rust-ammonia/ammonia/pull/243

https://github.com/rust-ammonia/ammonia/commit/b51bf4f9749ed3cd518330105f20a2c39c9ee274

https://github.com/rust-ammonia/ammonia/commit/7ac3fd3145236f28857eeecbadb544c8659cba31

https://github.com/rust-ammonia/ammonia/commit/004bf2cee4288f74a6ee619d589e3e90c24c09ca

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102241

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3

CVSS v4

EPSS