Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N R C L L N 6.1 .0023 13.8 —
AFFECTED Product Versions Fixed mistune < 3.2.1 – —
TIMELINE May 7 Reserved by GitHub_M May 26 EXPLOIT PUBLISHED — CVE-2026-44898 (lepture mistune). Public exploit reference added. May 26 Published (CNA: GitHub_M)
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_toc_ul() builds a <ul> table-of-contents tree from a list of (level, id, text) tuples. Both the id value (used as href="#<id>") and the text value (used as the visible link label) are inserted into <a> tags via a plain Python format string — with no HTML escaping applied to either value. When heading IDs are derived from user-supplied heading text (the standard use-case for readable slug anchors), an attacker can craft a heading whose text breaks out of the href="#..." attribute context, injecting arbitrary HTML tags including <script> blocks directly into the rendered TOC. This vulnerability is fixed in 3.2.1.
| Date | Event | Detail |
|---|---|---|
| May 7, 2026 | Reserved | Reserved by GitHub_M |
| May 26, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-44898 (lepture mistune). Public exploit reference added. |
| May 26, 2026 | Published | Published (CNA: GitHub_M) |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| lepture | mistune | — | < 3.2.1 | — |
Authoritative record: CVE-2026-44898 at cve.org
Vendors: lepture
Weaknesses: CWE-79
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-44898 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.