CVE-2026-49958Public exploitHinoki check available

Arbitrary file deletion via symlink-swap race

Published Jun 9, 2026 · Updated Jun 9, 2026

TOCTOU in Hermes WebUI before 0.51.303 allows local users to delete files outside the workspace through a raced Git discard. The git_discard function validates an untracked path with safe_resolve_ws, then passes it to Path.unlink or shutil.rmtree without anchoring deletion to the validated workspace. Exploitation requires workspace write access, user-triggered untracked-file discard, and a successful path-component symlink swap during the validation-to-deletion window.

CVSS severity4.3
Medium
EPSS probability0.08%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

TOCTOU in Hermes WebUI before 0.51.303 allows local users to delete files outside the workspace through a raced Git discard. The git_discard function validates an untracked path with safe_resolve_ws, then passes it to Path.unlink or shutil.rmtree without anchoring deletion to the validated workspace. Exploitation requires workspace write access, user-triggered untracked-file discard, and a successful path-component symlink swap during the validation-to-deletion window.

The record

CVE
CVE-2026-49958
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
Nathan Esquenazi
Product
Hermes WebUI
Classifications
CWE-367, T1485
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.51.303

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Nathan Esquenazi · Hermes WebUIversion=0 <0.51.303

Published CVSS scores

4.3VulnCheckCVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:A/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
5.0VulnCheckCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1485Data Destruction

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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