CyberRota Analysis
AI-GeneratedThe pymdown-extensions library, specifically versions up to 11.0, is vulnerable to a denial of service attack due to catastrophic backtracking in its inline processors when handling untrusted Markdown input. This vulnerability allows an unauthenticated remote attacker to exploit the rendering process, leading to unbounded CPU usage and potential service outages. Web applications that render user-supplied Markdown, such as comments or wikis, should prioritize updating to version 11.0.1 to mitigate this risk.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
Note: these links are listed for security research and verification purposes only.
Original NVD Description
pymdown-extensions is a collection of extensions for the Python Markdown library. In versions up to and including 11.0, four inline processors (caret, tilde, betterem, and magiclink) use regular expressions whose content groups can partition a run of delimiter characters in exponentially many ways, causing catastrophic backtracking. As a result, a single untrusted Markdown line under 50 bytes rendered with markdown.markdown() in each extension's default configuration drives the rendering thread into unbounded CPU usage that grows exponentially with input length, enabling an unauthenticated remote attacker who can submit Markdown to cause denial of service. The exposure is concrete for web applications that render user-supplied Markdown (comments, wikis, issue bodies, live preview), including any app using pymdownx.extra which bundles the vulnerable betterem default, as well as hosted docs/CI systems that build untrusted Markdown. The issue has been fixed in version 11.0.1.