Vulnerability in Nesquena Hermes-Webui

CVE-2026-49958

Hermes WebUI before version 0.51.303 contains a time-of-check time-of-use (TOCTOU) race condition vulnerability in the git_discard function within api/workspace_git.py that allows attackers to delete files outside the configured workspace boundary by replacing a validated path component with a symlink after validation but before deletion. Attackers can substitute a workspace-controlled path component with a symlink pointing to an external directory between the safe_resolve_ws() validation step and the subsequent Path.unlink() or shutil.rmtree() deletion call, causing the delete operation to follow the symlink and remove arbitrary files outside the workspace.

Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)

EPSS: 0.001 (0.2th percentile) — read the EPSS interpretation.