Description (CNA)
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parse_link_text. When parsing Markdown containing many consecutive [ characters, parse_link_text repeatedly scans the input using a regex search inside a loop. Each iteration re-scans a large portion of the remaining string, resulting in quadratic-time behavior. An attacker-controlled Markdown input can therefore trigger excessive CPU usage with a very small payload. This vulnerability is fixed in 3.3.0.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| lepture / mistune | affected < 3.3.0 |
CWE
CWE-400, CWE-770, CWE-407
References
ADP enrichment
No English description supplied.
A flaw was found in Mistune, a Python Markdown parser. A remote attacker can exploit this vulnerability by providing a specially crafted Markdown input containing many consecutive bracket characters. This can lead to excessive CPU usage, causing a denial-of-service (DoS) condition on the affected system.