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.

Attack Vector Local

Attack Complexity High

Privileges Required Low

Attack Requirements None

User Interaction Active

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity High

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
nesquena hermes-webui affected
Version Status Constraints
0 affected < 0.51.303

No data.

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/nesquena/hermes-webui/commit/4580f584964d640b95c4ffc9245a21ab926bec73 cve-icon cve-icon
https://github.com/nesquena/hermes-webui/pull/3702 cve-icon cve-icon cve-icon
https://github.com/nesquena/hermes-webui/pull/3756 cve-icon cve-icon
https://github.com/nesquena/hermes-webui/releases/tag/v0.51.303 cve-icon cve-icon
https://www.vulncheck.com/advisories/hermes-webui-toctou-race-condition-via-git-discard cve-icon cve-icon
History

Tue, 09 Jun 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 09 Jun 2026 17:15:00 +0000

Type Values Removed Values Added
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.
Title Hermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
Weaknesses CWE-367
References
Metrics cvssV3_1

{'score': 5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H'}

cvssV4_0

{'score': 4.3, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:A/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-06-09T18:26:54.848Z

Reserved: 2026-06-02T16:30:15.233Z

Link: CVE-2026-49958

cve-icon Vulnrichment

Updated: 2026-06-09T18:26:50.630Z

cve-icon NVD

Status : Deferred

Published: 2026-06-09T17:17:49.220

Modified: 2026-06-09T19:36:10.547

Link: CVE-2026-49958

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses