GHSA-mm7x-qfjj-5g2c: Ammonia Cross-Site Scripting Vulnerability

LOW
Share
CWE-79
Published
Advisory Summary

GHSA-mm7x-qfjj-5g2c is a LOW cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Ammonia libraries in the crates.io ecosystem. The issue involves ammonia incorrectly handles embedded svg and mathml leading to mutation xss after removal. Remediation is available by upgrading affected packages to version 4.1.2, 4.0.1, 3.3.1.

GHSA-mm7x-qfjj-5g2c at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-mm7x-qfjj-5g2c
Severity LOW
CVSS v3.1 Base Score N/A
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Ammonia
Package Ecosystem crates.io
Published Date
Last Updated

How to Fix GHSA-mm7x-qfjj-5g2c

To remediate this vulnerability, upgrade all affected Ammonia dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

ammonia fixed: 4.1.2 
Upgrade ammonia to 4.1.2
ammonia fixed: 4.0.1 
Upgrade ammonia to 4.0.1
ammonia fixed: 3.3.1 
Upgrade ammonia to 3.3.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for ammonia

How to Check if You Are Affected

To determine whether your application is affected by GHSA-mm7x-qfjj-5g2c, inspect your project dependencies for Ammonia:

inspect dependencies for ammonia

Analyze the terminal output to locate any version of Ammonia in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.1.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where 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. In Ammonia, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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

GHSA-mm7x-qfjj-5g2c Affected Ammonia Versions

3 component(s)
Fixed Versions:
4.1.24.0.13.3.1
Product / Package Ecosystem Affected Versions Fixed Version
ammonia
 crates.io
≥ 4.1.0
< 4.1.2
4.1.2
ammonia
 crates.io
≥ 4.0.0
< 4.0.1
4.0.1
ammonia
 crates.io
< 3.3.1
3.3.1

References

Ammonia Source Repository REPOSITORY
https://github.com/rust-ammonia/ammonia
Security Fix Commit FIX COMMIT
https://github.com/rust-ammonia/ammonia/commit/de0297111a3a1273275b670960bcd47a0481718e
rustsec.org/advisories/rustsec-... WEB
https://rustsec.org/advisories/RUSTSEC-2025-0071.html

Frequently Asked Questions

What is GHSA-mm7x-qfjj-5g2c?
GHSA-mm7x-qfjj-5g2c is a security vulnerability in Ammonia involving Ammonia incorrectly handles embedded SVG and MathML leading to mutation XSS after removal under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Ammonia versions are affected?
Affected versions include releases prior to 4.1.2, 4.0.1, 3.3.1 across affected packages: ammonia.
What version fixes GHSA-mm7x-qfjj-5g2c?
Upgrading to 4.1.2, 4.0.1, 3.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ammonia affected?
Yes, ammonia is affected in releases prior to 4.1.2, 4.0.1, 3.3.1. Upgrade your dependency to 4.1.2, 4.0.1, 3.3.1 or later.
What CWE is associated with GHSA-mm7x-qfjj-5g2c?
GHSA-mm7x-qfjj-5g2c is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (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.).
How can I check crates.io dependencies for GHSA-mm7x-qfjj-5g2c?
Run the dependency tree command: 'inspect dependencies for ammonia'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-mm7x-qfjj-5g2c",
  "modified" : "2025-09-22T15:40:15Z",
  "published" : "2025-09-22T15:40:15Z",
  "aliases" : [ ],
  "summary" : "Ammonia incorrectly handles embedded SVG and MathML leading to mutation XSS after removal",
  "details" : "Affected versions of this crate did not correctly strip namespace-incompatible tags\nin certain situations, causing it to incorrectly account for differences between HTML,\nSVG, and MathML.\n\nThis vulnerability only has an effect when the `svg` or `math` tag is allowed,\nbecause it relies on a tag being parsed as html during the cleaning process, but\nserialized in a way that causes in to be parsed as xml by the browser.\n\nAdditionally, the application using this library must allow a tag that is parsed as raw text in HTML.\nThese [elements] are:\n\n* title\n* textarea\n* xmp\n* iframe\n* noembed\n* noframes\n* plaintext\n* noscript\n* style\n* script\n\nApplications that do not explicitly allow any of these tags should not be affected, since none are allowed by default.\n\n[elements]: https://github.com/servo/html5ever/blob/57eb334c0ffccc6f88d563419f0fbeef6ff5741c/html5ever/src/tree_builder/rules.rs",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ammonia"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.1.0"
      }, {
        "fixed" : "4.1.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ammonia"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "4.0.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "crates.io",
      "name" : "ammonia"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.3.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/rust-ammonia/ammonia/commit/de0297111a3a1273275b670960bcd47a0481718e"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rust-ammonia/ammonia"
  }, {
    "type" : "WEB",
    "url" : "https://rustsec.org/advisories/RUSTSEC-2025-0071.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-09-22T15:40:15Z",
    "nvd_published_at" : null
  }
}