Vulnerability details
CVE-2026-76098
lepture mistune
Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown
CVSS 3.1
7.5High
Official description
Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.render_token() can exceed Python's recursion limit and raise RecursionError, allowing crafted Markdown to crash a parsing process. This issue is fixed in version 3.3.3
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (GitHub_M) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| lepture | mistune | >= 3.3.0, < 3.3.3 | CVEProject cvelistV5 (CNA) |
References and advisories
2- https://github.com/lepture/mistune/commit/0938fb7 x_refsource_MISC
- https://github.com/lepture/mistune/security/advisories/GHSA-6m44-fpc8-c3rq x_refsource_CONFIRM
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Details
- Published
- 2026-08-24
- Last updated
- 2026-08-24
- State
- Published
- Assigner (CNA)
- GitHub_M
Exploit prediction (EPSS)
0.48%
Probability of exploitation in 30 days
42.2%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- Proof of concept
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-674Uncontrolled Recursion