Detections
Analytics
CVE-2026-71488
high
Description
league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 0.6.0 until 2.9.0, specially crafted Markdown lines can cause the parser to have quadratic time complexity when converting, because several parsing paths repeatedly rescan growing portions of a line to translate between character positions and byte positions, and the Autolink extension can also copy and validate the remaining line at every URL-like prefix, allowing an attacker who can submit Markdown for conversion to consume disproportionate CPU time with a comparatively small request. This issue is fixed in 2.9.0.
References
https://github.com/thephpleague/commonmark/security/advisories/GHSA-2q4p-g7hv-5rgv
https://github.com/thephpleague/commonmark/releases/tag/2.9.0
https://github.com/thephpleague/commonmark/commit/c97b02e5e652b992033b93ba5d6182f706343fc6
https://github.com/thephpleague/commonmark/commit/a70979ea0d7d3377bd7127536748454a922bf5eb
https://github.com/thephpleague/commonmark/commit/a6ef6cdc308dfa39a34239c35818e75892a0e6a8