CVE-2026-28465
Published: 05 March 2026
Summary
CVE-2026-28465 is a high-severity Authentication Bypass by Spoofing (CWE-290) vulnerability in Openclaw Openclaw. Its CVSS base score is 8.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 29.1th 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-3 (Access Enforcement) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2026-28465, published on 2026-03-05, is an improper authentication vulnerability (CWE-290) in the webhook verification mechanism of OpenClaw's voice-call plugin. Versions of the plugin prior to 2026.2.3 trust untrusted forwarded headers, such as Forwarded or X-Forwarded-* headers, enabling remote attackers to bypass authentication checks. This issue arises in reverse-proxy configurations that implicitly pass and trust these headers without proper validation.
Remote, unauthenticated attackers (PR:N) with network access (AV:N) can exploit the vulnerability by manipulating the affected headers in HTTP requests forwarded through a misconfigured proxy. Exploitation requires high complexity (AC:H) and no user interaction (UI:N), allowing attackers to spoof webhook events. Successful exploitation results in high integrity impact (I:H) with no confidentiality or availability effects (C:N/A:N) and unchanged scope (S:U), as reflected in the CVSS v3.1 base score of 5.9.
Mitigation is addressed in OpenClaw's GitHub security advisory (GHSA-3m3q-x3gj-f79x) and a specific commit (a749db9820eb6d6224032a5a34223d286d2dcc2f) that patches the verification logic. Security practitioners should update the voice-call plugin to version 2026.2.3 or later. Additional details on the bypass via forwarded headers are provided in the VulnCheck advisory.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9911
Vulnerability details
OpenClaw's voice-call plugin versions before 2026.2.3 contain an improper authentication vulnerability in webhook verification that allows remote attackers to bypass verification by supplying untrusted forwarded headers. Attackers can spoof webhook events by manipulating Forwarded or X-Forwarded-* headers in reverse-proxy configurations…
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that implicitly trust these headers.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The CVE describes an authentication bypass in a publicly accessible webhook endpoint (via untrusted X-Forwarded-* headers in a reverse-proxy setup), which directly matches the definition of exploiting a public-facing application to gain unauthorized access and spoof events.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces proper authentication decisions on incoming webhook requests instead of accepting spoofed Forwarded/X-Forwarded-* headers.
Requires validation of all HTTP header inputs so that untrusted proxy headers cannot be used to bypass webhook authentication.
Boundary-protection mechanisms (including reverse-proxy configuration) must not implicitly trust Forwarded headers from external sources.