Mistune 3.2.1 before 3.3.0 CSS Injection via Figure Directive figwidth Option
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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 3.3.0
- 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
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
Mistune, a Python Markdown parser, is affected when rendering untrusted markdown that uses its figure directive. Attackers can inject arbitrary CSS through the unvalidated figwidth option, which can make victim browsers send requests to attacker-controlled servers and leak information.
Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.
Read the original description
Mistune from 3.2.1 before 3.3.0 contains a CSS injection vulnerability that allows attackers controlling markdown input to inject arbitrary style declarations via the unvalidated figwidth option of the figure directive. Attackers can append declarations like background:url() to the rendered figure style attribute, forcing victim browsers to send requests to attacker servers and leak attribute values.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- lepture mistune
From 3.2.1 · fixed in 3.3.0