CVE-2026-15311

Name of the Vulnerable Software and Affected Versions NousResearch hermes-agent versions prior to 2026.5.29.3

Description A remote cross site scripting issue exists within the Matrix Adapter component. The flaw is located in the MatrixAdapter. markdown to html() function within the gateway/platforms/matrix.py file, where improper manipulation of input allows for the execution of malicious scripts.

Recommendations As a temporary workaround, restrict the use of the MatrixAdapter. markdown to html() function until a patch is officially released.