VDB-372087 · CVE-2026-53869 · GCVE-0-2026-53869

NousResearch hermes-agent up to 0.15.x on WebSocket WebSocket Endpoint /api/pty missing authentication

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.3	$0-$5k	0.84

Summaryinfo

A vulnerability identified as critical has been detected in NousResearch hermes-agent up to 0.15.x on WebSocket. Affected by this issue is some unknown functionality of the file /api/pty of the component WebSocket Endpoint. Performing a manipulation results in missing authentication. This vulnerability is reported as CVE-2026-53869. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in NousResearch hermes-agent up to 0.15.x on WebSocket. This affects some unknown functionality of the file /api/pty of the component WebSocket Endpoint. The manipulation with an unknown input leads to a missing authentication vulnerability. CWE is classifying the issue as CWE-306. The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. This is going to have an impact on availability. The summary by CVE is:

Hermes Agent before 0.16.0 contains a DNS rebinding vulnerability in WebSocket endpoints that allows remote attackers to bypass Host and Origin validation. FastAPI HTTP middleware does not execute for WebSocket upgrade requests on /api/pty, /api/ws, /api/pub, and /api/events endpoints, enabling attackers to exploit DNS rebinding and inject malicious commands or read terminal output.

The weakness was disclosed by Chia Min Jun Lennon. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-53869 since 06/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 0.16.0 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

NousResearch

Name

hermes-agent

Version

Website

Product: https://github.com/NousResearch/hermes-agent/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Missing authentication
CWE: CWE-306 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: hermes-agent 0.16.0

Timelineinfo

06/10/2026 CVE reserved
06/17/2026 +7 days Advisory disclosed
06/17/2026 +0 days VulDB entry created
06/17/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Researcher: Chia Min Jun Lennon
Status: Confirmed

CVE: CVE-2026-53869 (🔒)
GCVE (CVE): GCVE-0-2026-53869
GCVE (VulDB): GCVE-100-372087

Entryinfo

Created: 06/17/2026 20:45
Changes: 06/17/2026 20:45 (80)
Complete: 🔍
Cache ID: 216::103