high7.5
CVE-2026-86428
commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes.
Impact
commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Thephpleague | Commonmark | from 1.5.0 before 2.10.0 |