Medium 4.7Published Oct 22, 2026

CVE-2026-115351Mistune 3.2.1 before 3.3.0 CSS Injection via Figure Directive figwidth Option

Updated under an hour ago (Oct 28, 2026, 1:10 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for lepture mistune

Exploited in the last 30 days

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.

CVSS: 4.7 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
Weakness (CWE): CWE-94
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Oct 22, 2026
First seen by InfoSec Signals: Oct 22, 2026

Affected products

Affected products

lepture mistune lepture:mistune (from the name)	from 3.2.1 before 3.3.0; 3.3.0 not affected	CNA record

References

References

https://github.com/lepture/mistune/security/advisories/GHSA-xmwc-wjpr-q378	vendor-advisory
https://www.vulncheck.com/advisories/mistune-3.2.1-before-3.3.0-css-injection-via-figure-directive-figwidth-option	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.