🛡️ GHSA-mm7x-qfjj-5g2c — ammonia

🟢 CVSS 2.0 — Low ✅ No Known Exploit CWE-79 OSV
2.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Ammonia incorrectly handles embedded SVG and MathML leading to mutation XSS after removal

Affected versions of this crate did not correctly strip namespace-incompatible tags

in certain situations, causing it to incorrectly account for differences between HTML,

SVG, and MathML.

This vulnerability only has an effect when the svg or math tag is allowed,

because it relies on a tag being parsed as html during the cleaning process, but

serialized in a way that causes in to be parsed as xml by the browser.

Additionally, the application using this library must allow a tag that is parsed as raw text in HTML.

These [elements] are:

  • title
  • textarea
  • xmp
  • iframe
  • noembed
  • noframes
  • plaintext
  • noscript
  • style
  • script

Applications that do not explicitly allow any of these tags should not be affected, since none are allowed by default.

[elements]: https://github.com/servo/html5ever/blob/57eb334c0ffccc6f88d563419f0fbeef6ff5741c/html5ever/src/tree_builder/rules.rs

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. Rated impact: confidentiality none, integrity none, availability none.

Weakness class

GHSA-mm7x-qfjj-5g2c is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

GHSA-mm7x-qfjj-5g2c is recorded against 1 package.

  • ammonia

Timeline and source

Published on 22 September 2025 and last revised on 4 February 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Web)
github.com (Package)
rustsec.org (Web)

Details

Severity LOW
CVSS Score 2.0
CVSS Vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U
CWE CWE-79
Public Exploit ✅ No
Source OSV
Published 2025-09-22
Updated 2026-08-20
Modified 2026-02-04
Fix URL N/A

Affected Packages

Software From version Fixed in
ammonia — —

Similar Threats

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