CVE-2026-49973

critical

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.

References

https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-password-takeover-via-api-settings

https://github.com/nesquena/hermes-webui/releases/tag/v0.51.358

https://github.com/nesquena/hermes-webui/pull/3973

https://github.com/nesquena/hermes-webui/pull/3964

https://github.com/nesquena/hermes-webui/commit/1126e541325d401538f6a272a9c024c37d47ae08

Details

Source: Mitre, NVD

Published: 2026-06-11

Updated: 2026-06-11

Risk Information

CVSS v2

Base Score: 9.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:P

Severity: High

CVSS v3

Base Score: 9.4

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L

Severity: Critical

CVSS v4

Base Score: 9.2

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Severity: Critical

EPSS

EPSS: 0.00072