CVE-2026-8630GHSA-QVC2-MG72-JJHX
justhtml before 1.12.0 Mutation XSS via Raw Text Elements
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 1.12.0
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
CISA's decision points: whether it is exploited, whether attacks can be automated, and how much control an attacker gets. Assessed (SSVC 2.0.3).What do these mean? →
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
justhtml before 1.12.0 (versions <= 1.11.0) contains a mutation cross-site scripting (mXSS) vulnerability in the serialization of raw-text elements such as <style> and <script>. When a DOM tree is processed by sanitize_dom() using a custom policy that keeps these elements, text nodes inside them are serialized literally without escaping, allowing attacker-controlled text containing the matching closing tag sequence to break out of the raw-text context and inject arbitrary HTML into the serialized output. The default sanitization policy is not affected because it drops the contents of style and script.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- EmilStenstrom justhtml
fixed in 1.12.0
- justhtmlPyPI
fixed in 1.12.0