High severity7.5NVD Advisory· Published Oct 29, 2026
CVE-2019-25781
CVE-2019-25781
Description
Python-Markdown 3.0 through 3.11.2 contains an algorithmic complexity vulnerability in inline link parsing that allows remote attackers to exhaust CPU through unmatched brackets. Attackers can submit short Markdown containing repeated [ or ![ characters, forcing LinkInlineProcessor.getText() and getLink() into quadratic scans that keep workers busy for minutes.
Patches
Vulnerability mechanics
References
4- github.com/Python-Markdown/markdown/blob/b41e0aaf1181f1a8cb200cf5a815aad7c0020d23/markdown/inlinepatterns.pynvd
- github.com/Python-Markdown/markdown/issues/1654nvd
- github.com/Python-Markdown/markdown/issues/798nvd
- www.vulncheck.com/advisories/python-markdown-3.0-through-3.11.2-denial-of-service-via-link-bracket-parsingnvd
News mentions
0No linked articles in our index yet.