xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS
xhtml-purifier does not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix HTML-entity-encodes attribute values before serialization.
GHSA-j8r4-32c5-33rc
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-j8r4-32c5-33rc
xhtml-purifier
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 0.4.3
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.4.3"
}
]
}
],
"package": {
"name": "xhtml-purifier",
"purl": "pkg:npm/xhtml-purifier",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-j8r4-32c5-33rc/GHSA-j8r4-32c5-33rc.json",
"last_known_affected_version_range": "<= 0.4.1"
}
}
]- Related CVEs
- CVE-2026-61784
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #14229 · Revision 1
- Added to Heist Feed
- Publisher date