RUSTSEC-2026-0533

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Source

https://rustsec.org/advisories/RUSTSEC-2026-0533

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0533.json

JSON Data

https://api.osv.dev/v1/vulns/RUSTSEC-2026-0533

Aliases

GHSA-934p-vp7m-gx3c

Published

2026-11-12T12:00:00Z

Modified

2026-11-13T12:45:09Z

Summary

Incorrect handling of embedded SVG and MathML leads to mutation XSS

Details

The MathML text integration points (mi, mo, mn, ms, mtext) and SVG foreignObject can be made to contain a tag in the other one's namespace (a MathML integration point with a child in the SVG namespace, or vice versa) without the root tag that switches out of the HTML namespace. If the attacker can construct input that parses differently in as HTML than as foreign XML, they can inject arbitrary JavaScript code into the user's browser.

For example:

The user writes <math><mi><svg><gadget></svg></mi></math>.
The application enables math, mi, and the gadget, but not svg.
Ammonia filters the input to <math><mi><gadget></mi></math>.
Because svg is now gone, the gadget switches from being parsed as SVG to being parsed as HTML.
The gadget is written in such a way that it exploits the parsing differences between HTML and MathML.

As far as we know, the gadget can only be written using 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.

This vulnerability was reported by Roger Meyer.

Database specific

{
    "license": "CC0-1.0"
}

References

Affected packages

crates.io / ammonia

Package

Name: ammonia; View open source insights on deps.dev
Purl: pkg:cargo/ammonia

Affected ranges

Type: SEMVER
Events: Introduced

0.0.0-0

Fixed

3.3.5

Introduced

4.0.0

Fixed

4.1.9

Introduced

4.2.0

Fixed

4.2.5

Ecosystem specific

{
    "affected_functions": null,
    "affects": {
        "arch": [],
        "functions": [],
        "os": []
    }
}