Skip to main content
Mallory
CriticalPublic exploit

Unauthenticated initial setup takeover in Hermes WebUI

IdentifiersCVE-2026-49973CWE-306· Missing Authentication for…

CVE-2026-49973 is an improper access control vulnerability in Hermes WebUI before version 0.51.358. During the first-run setup flow, the settings API endpoint accepts the _set_password parameter without enforcing appropriate authentication or network-origin restrictions. An unauthenticated remote attacker on any reachable network can send a POST request to the settings endpoint during this initialization window, set an arbitrary password hash, and complete takeover of the initial setup process. The issue effectively exposes privileged setup functionality to unauthenticated users before the legitimate operator finishes provisioning the instance.

Share:
For your environment

Are you exposed to this one?

Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.

ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unauthenticated attacker to seize administrative control of a Hermes WebUI instance during initial setup. The attacker can persist an arbitrary password hash, obtain a valid session cookie, and deny the legitimate operator access to their own deployment. Based on the provided CVSS context, the impact is high for confidentiality and integrity and low for availability, reflecting full unauthorized administrative access with resulting account takeover and operator lockout.

Mitigation

If you can’t patch tonight, do this now.

Until the fixed version can be deployed, restrict network exposure of Hermes WebUI during first-run initialization. Limit access to trusted hosts or local networks only, and prevent untrusted remote access to the settings API endpoint until setup has been completed.

Remediation

Patch, then assume compromise.

Upgrade Hermes WebUI to version 0.51.358 or later, which contains the fix for the improper access control condition in the initial setup flow.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
HermesWebuiapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.
Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity6

Community discussion across Reddit, Mastodon, and other social sources.