What’s Vulnerable › Vulnerabilities

CVE-2026-49973: Hermes WebUI < 0.51.358 Unauthenticated Password Takeover via /api/settings

• Severity: critical (CVSS 9.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-11 · updated 2026-10-26
• Weakness: CWE-306

Description

Hermes WebUI before version 0.51.358 contains an improper access control vulnerability that allows unauthenticated remote attackers to hijack initial setup by submitting the _set_password parameter to the settings API endpoint without any network origin restriction. Attackers on any reachable network can send a POST request to the settings endpoint during the first-run setup window to persist an arbitrary password hash, obtain a valid session cookie, and lock out the legitimate operator from their own instance.

Affected products

• nesquena hermes-webui: before 0.51.358 — fixed in 0.51.358

How to fix

Upgrade to a fixed version: nesquena hermes-webui 0.51.358. Check the vendor advisory for mitigations.

References

• https://github.com/nesquena/hermes-webui/commit/1126e541325d401538f6a272a9c024c37d47ae08
• https://github.com/nesquena/hermes-webui/pull/3964
• https://github.com/nesquena/hermes-webui/pull/3973
• https://github.com/nesquena/hermes-webui/releases/tag/v0.51.358
• https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-password-takeover-via-api-settings
• https://github.com/nesquena/hermes-webui/pull/3964

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