CVE-2026-49958
Hermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
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 profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- Active
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
4.3
Hermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
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.
- Record
CVE-2026-49958- CVSS 4.0
- 4.3 Medium
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 - CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H - Weakness
- CWE-367
- Updated
- 2026-11-02
EUVDEUVD-2026-35706
4.3
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.
- Record
EUVD-2026-35706- CVSS 4.0
- 4.3 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qg92-vxjm-x4q9
4.3
Hermes WebUI before version 0.51.303 contains a time-of-check time-of-use (TOCTOU) race condition...
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.
- Record
GHSA-qg92-vxjm-x4q9- CVSS 4.0
- 4.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H - Weakness
- CWE-367
- Updated
- 2026-11-02
NVD
4.3
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.
- Record
CVE-2026-49958- CVSS 4.0
- 4.3 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H - Weakness
- CWE-367
- Updated
- 2026-11-02
OSV
4.3
Hermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
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.
- Record
CVE-2026-49958- CVSS 4.0
- 4.3 Medium
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 - Weakness
- CWE-367
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-49958 is a medium vulnerability (CVSS 4.3) in Nesquena Hermes-webui, published June 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.08%, the 0th percentile. No source names a fixed version.
References
github.com/nesquena/hermes-webui/releases/tag/v0.51.303
github.com/nesquena/hermes-webui/pull/3702
github.com/nesquena/hermes-webui/pull/3756
github.com/nesquena/hermes-webui/commit/4580f584964d640b95c4ffc9245a21ab926bec73
vulncheck.com/advisories/hermes-webui-toctou-race-condition-via-git-discard
nvd.nist.gov/vuln/detail/CVE-2026-49958
github.com/advisories/GHSA-qg92-vxjm-x4q9
github.com/CVEProject/cvelistV5/tree/main/cves/2026/49xxx/CVE-2026-49958.json
github.com/nesquena/hermes-webui