Cyber Posture

CVE-2026-28458

HighPublic PoC

Published: 05 March 2026

Published
05 March 2026
Modified
09 March 2026
KEV Added
Patch
CVSS Score 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0008 23.2th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-28458 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Openclaw Openclaw. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked at the 23.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 AC-14 (Permitted Actions Without Identification or Authentication) and IA-9 (Service Identification and Authentication).

Threat & Defense at a Glance

What attackers do: exploitation maps to Browser Session Hijacking (T1185) and 2 other techniques. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

AC-14 requires organizations to identify and restrict permitted actions without identification or authentication, directly addressing the unauthenticated access to the /cdp WebSocket endpoint.

prevent

IA-9 mandates identification and authentication for system services prior to allowing access requests, preventing unauthorized connections to the Browser Relay /cdp endpoint.

prevent

SI-2 ensures timely remediation of flaws through patching, directly mitigating this vulnerability by applying the fixed version 2026.2.1 that adds authentication tokens.

MITRE ATT&CK Enterprise TechniquesAI

T1185 Browser Session Hijacking Collection
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.
T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1606.001 Web Cookies Credential Access
Adversaries may forge web cookies that can be used to gain access to web applications or Internet services.
Why these techniques?

Missing auth on localhost WebSocket (/cdp) directly enables malicious websites (drive-by) to steal cookies and execute JS across tabs, mapping to browser session hijacking and web cookie theft.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

OpenClaw version 2026.1.20 prior to 2026.2.1 contains a vulnerability in the Browser Relay (extension must be installed and enabled) /cdp WebSocket endpoint in which it does not require authentication tokens, allowing websites to connect via loopback and access sensitive data.…

more

Attackers can exploit this by connecting to ws://127.0.0.1:18792/cdp to steal session cookies and execute JavaScript in other browser tabs.

Deeper analysisAI

CVE-2026-28458 is a missing authentication vulnerability (CWE-306) in OpenClaw version 2026.1.20 prior to 2026.2.1, affecting the Browser Relay component when its extension is installed and enabled. The issue lies in the /cdp WebSocket endpoint, which does not require authentication tokens. This allows websites to connect via loopback to access sensitive data. The vulnerability carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N).

Remote attackers can exploit this vulnerability by tricking users into visiting a malicious website, requiring only low attack complexity and user interaction. From the malicious site, attackers connect to ws://127.0.0.1:18792/cdp, enabling them to steal session cookies and execute JavaScript in other browser tabs, resulting in high impacts to confidentiality and integrity.

Advisories recommend upgrading to OpenClaw version 2026.2.1 to mitigate the issue. The patching commit is available at https://github.com/openclaw/openclaw/commit/a1e89afcc19efd641c02b24d66d689f181ae2b5c, with further details in the GitHub security advisory at https://github.com/openclaw/openclaw/security/advisories/GHSA-mr32-vwc2-5j6h and the VulnCheck advisory at https://www.vulncheck.com/advisories/openclaw-missing-authentication-in-browser-relay-cdp-websocket-endpoint.

Details

CWE(s)

Affected Products

openclaw
openclaw
2026.1.20 — 2026.2.1

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References