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…
Does this matter?
Lower severity and a low EPSS score (0.08%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 4.3 MEDIUMCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:A/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.08% probability · 0th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Source
- disclosure@vulncheck.com
References
- https://github.com/nesquena/hermes-webui/commit/4580f584964d640b95c4ffc9245a21ab926bec73
- https://github.com/nesquena/hermes-webui/pull/3702
- https://github.com/nesquena/hermes-webui/pull/3756
- https://github.com/nesquena/hermes-webui/releases/tag/v0.51.303
- https://www.vulncheck.com/advisories/hermes-webui-toctou-race-condition-via-git-discard
- https://github.com/nesquena/hermes-webui/pull/3702
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.