CVE-2026-115351GHSA-xmwc-wjpr-q378
Mistune 3.2.1 before 3.3.0 CSS Injection via Figure Directive figwidth Option
lepture mistune
CVSS
5.3MediumExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.22%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 3.3.0mistuneCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
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.
Text from CVE List
Affected versions 2
- mistuneaffected: 3.2.1 before 3.3.0CVE List
- mistuneunaffected: 3.3.0CVE List