Vulnerability · Published Jun 11, 2026 · Assigned by VulnCheck

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

Critical 9.4

In plain English

A critical-severity missing authentication in hermes-webui from nesquena. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).

Severity (CVSS 3.1)9.4Critical

Exploit odds (30 days)0.5%top 54.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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 (as reported)

Vendor	Product	Versions
nesquena	hermes-webui	0 – before 0.51.358

Weakness: CWE-306 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

References

https://github.com/nesquena/hermes-webui/releases/tag/v0.51.358 release-notes
https://github.com/nesquena/hermes-webui/pull/3964 issue-tracking
https://github.com/nesquena/hermes-webui/pull/3973 issue-tracking
https://github.com/nesquena/hermes-webui/commit/1126e541325d401538f6a272a9c024c37d47ae08 patch
https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-password-takeover-via-api-settings third-party-advisory