CVE-2026-49973 Hermes WebUI < 0.51.358 Unauthenticated Password Takeover via /api/settings
Unauthenticated attackers can hijack initial setup by setting a password via the settings API, locking out legitimate users and gaining administrative access.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-49973?
CVE-2026-49973 is a critical missing authorization vulnerability in nesquena hermes-webui, published on 11 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-306
Which versions are affected by CVE-2026-49973?
How do I fix CVE-2026-49973?
No fix has been published for CVE-2026-49973 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-49973 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49973 exists.
Sources
Also known as GHSA-p52p-4vmg-4vq3.