CVE-2026-114463

Deferred Deferred - Pending Action

Authentication Bypass in Nous Research Hermes Agent via Malicious Webhook Route

Publication date: 2026-10-21

Last updated on: 2026-10-30

Assigner: CERT/CC

Description

The webhook platform gateway in Nous Research Hermes Agent versions builds the session chat_id as webhook:{route_name}:{delivery_id} and re-derives the authorizing route by splitting that string, so a route name containing a ":" resolves toolset authorization to a different, higher-privileged prefix route than the one authenticated, which allows a remote attacker with the target HMAC to gain that higher-privileged route's toolsets.

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Meta Information

Published

2026-10-21

Last Modified

2026-10-30

Generated

2026-11-10

AI Q&A

2026-10-22

EPSS Evaluated

2026-11-09

NVD

CVE-2026-114463

EUVD

EUVD-2026-107306

Affected Vendors & Products

Vendor	Product	Version / Range
Nous Research	Hermes Agent	0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-863	The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.

Attack-Flow Graph

Executive Summary

CVE-2026-114463 is a privilege escalation flaw in the Hermes Agent webhook platform. It occurs when route names contain colons. The system incorrectly parses the route name from session chat IDs, assigning toolsets from higher-privileged routes to lower-privileged ones. For example, a route named 'build:external' may inherit toolsets from the 'build' route, granting access to terminal and file tools.

Detection Guidance

To detect this vulnerability, review Hermes Agent logs for routes containing colons in their names. Check for requests to low-privileged routes (e.g., build:external) that unexpectedly access high-privileged toolsets like terminal or file system tools. Look for mismatches between the intended route and the resolved route in access logs.

Impact Analysis

An attacker with the HMAC secret of a low-privileged route could exploit this to gain access to higher-privileged toolsets. This may allow command execution on the host, access to sensitive files, or file modifications. The impact depends on the toolsets assigned to the higher-privileged route.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data or system commands, which may violate compliance requirements under GDPR (e.g., unauthorized data access or processing) and HIPAA (e.g., unauthorized access to protected health information). The flaw allows privilege escalation, enabling attackers to execute commands or access files on the host system, potentially exposing regulated data.

Mitigation Strategies

Upgrade Hermes Agent to version 0.22.2 or later, which includes the fix for this issue.
Rename any webhook routes containing colons to avoid the ambiguity in route resolution.
Rotate any shared integration secrets or HMAC keys that may have been exposed due to this vulnerability.
Monitor logs for suspicious activity on routes with colons, especially those accessing privileged toolsets.

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