Hermes WebUI < 0.51.303 TOCTOU Race Condition via git_discard
Summary
| CVE | CVE-2026-49958 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-09 17:17:49 UTC |
| Updated | 2026-06-09 19:36:10 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 4.3 MEDIUM from [email protected]
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
EPSS: 0.000810000 probability, percentile 0.002830000 (date 2026-06-16)
Problem Types: CWE-367 | CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | CVSS | 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 |
| 3.1 | [email protected] | Secondary | 5 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H |
| 3.1 | CNA | CVSS | 5 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
HighAttack Requirements
NonePrivileges Required
LowUser Interaction
ActiveConfidentiality
NoneIntegrity
LowAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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 v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
LowUser Interaction
RequiredScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
HighCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Nesquena | Hermes-webui | affected 0.51.303 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/nesquena/hermes-webui/pull/3702 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/nesquena/hermes-webui/pull/3756 | [email protected] | github.com | |
| github.com/nesquena/hermes-webui/commit/4580f584964d640b95c4ffc9245a21ab... | [email protected] | github.com | |
| github.com/nesquena/hermes-webui/releases/tag/v0.51.303 | [email protected] | github.com | |
| www.vulncheck.com/advisories/hermes-webui-toctou-race-condition-via-git-discard | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Chia Min Jun Lennon (en)
There are currently no legacy QID mappings associated with this CVE.