PYSEC-2026-89
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/markdown/PYSEC-2026-89.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-89
- Aliases
- Published
- 2026-03-05T15:16:11.243Z
- Modified
- 2026-05-21T15:00:15.862067676Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- [none]
- Details
-
Python-Markdown version 3.8 contain a vulnerability where malformed HTML-like sequences can cause html.parser.HTMLParser to raise an unhandled AssertionError during Markdown parsing. Because Python-Markdown does not catch this exception, any application that processes attacker-controlled Markdown may crash. This enables remote, unauthenticated Denial of Service in web applications, documentation systems, CI/CD pipelines, and any service that renders untrusted Markdown. The issue was acknowledged by the vendor and fixed in version 3.8.1. This issue causes a remote Denial of Service in any application parsing untrusted Markdown, and can lead to Information Disclosure through uncaught exceptions.
- References
Affected packages
PyPI / markdown
Package
- Name
- markdown
- View open source insights on deps.dev
- Purl
- pkg:pypi/markdown
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedLast affected3.8
Affected versions
1.*
1.7
2.*
2.0
2.0.1
2.0.2
2.0.3
2.1.0
2.1.1
2.2.0
2.2.1
2.3
2.3.1
2.4
2.4.1
2.5
2.5.1
2.5.2
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.6.5
2.6.6
2.6.7
2.6.8
2.6.9
2.6.10
2.6.11
3.*
3.0
3.0.1
3.1
3.1.1
3.2
3.2.1
3.2.2
3.3
3.3.1
3.3.2
3.3.3
3.3.4
3.3.5
3.3.6
3.3.7
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.5
3.5.1
3.5.2
3.6
3.7
3.8