CVE-2026-49958
MEDIUMHermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
Title source: cnaDescription
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.
References (5)
Core 5
Core References
Issue Tracking issue-tracking
https://github.com/nesquena/hermes-webui/pull/3756
Release Notes release-notes
https://github.com/nesquena/hermes-webui/releases/tag/v0.51.303
Technical Description technical-description
https://github.com/nesquena/hermes-webui/pull/3702
Patch patch
https://github.com/nesquena/hermes-webui/commit/4580f584964d640b95c4ffc9245a21ab926bec73
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/hermes-webui-toctou-race-condition-via-git-discard
Scores
CVSS v3
5.0
EPSS
0.0001
EPSS Percentile
1.8%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-367
Status
published
Products (1)
nesquena/hermes-webui
< 0.51.303
Published
Jun 09, 2026
Tracked Since
Jun 09, 2026