CVE-2026-42423
Published: 28 April 2026
Summary
CVE-2026-42423 is a high-severity Failing Open (CWE-636) vulnerability in Openclaw Openclaw. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14.6th 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 SC-24 (Fail in Known State) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Requires timely identification, reporting, and correction of software flaws like the approval-timeout fallback bypass in OpenClaw prior to 2026.4.8, preventing unauthorized inline eval execution.
Mandates failure to a secure state upon errors such as timeouts, directly countering the insecure fallback that bypasses strictInlineEval explicit-approval requirements.
Enforces least privilege to restrict the impact of low-privilege (PR:L) attackers exploiting the timeout fallback for unauthorized inline eval commands on gateway and node hosts.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability bypasses explicit approval for inline eval commands on network-accessible gateway and node exec hosts, directly enabling exploitation of a public-facing application (T1190) to achieve unauthorized command/script execution (T1059).
NVD Description
OpenClaw before 2026.4.8 contains an approval-timeout fallback mechanism that bypasses strictInlineEval explicit-approval requirements on gateway and node exec hosts. Attackers can exploit this timeout fallback to execute inline eval commands that should require explicit user approval, circumventing the intended security…
more
boundary.
Deeper analysisAI
CVE-2026-42423 affects OpenClaw versions prior to 2026.4.8 and involves an approval-timeout fallback mechanism that bypasses the strictInlineEval explicit-approval requirements on gateway and node exec hosts. This vulnerability, classified under CWE-636 (Not Failing Securely), allows attackers to execute inline eval commands that are intended to require explicit user approval, thereby circumventing the designed security boundary. The issue received a CVSS v3.1 base score of 7.5 (AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) and was published on 2026-04-28.
Attackers with low privileges (PR:L) can exploit this vulnerability over the network (AV:N), though it requires high attack complexity (AC:H) and no user interaction (UI:N). Successful exploitation enables high-impact confidentiality, integrity, and availability compromises (C:H/I:H/A:H) within the unchanged scope (S:U), specifically by leveraging the timeout fallback to run unauthorized inline eval commands on affected hosts.
Mitigation is addressed in OpenClaw 2026.4.8, with a fixing commit available at https://github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5. Additional details are provided in the GitHub security advisory at https://github.com/openclaw/openclaw/security/advisories/GHSA-q2gc-xjqw-qp89 and the VulnCheck advisory at https://www.vulncheck.com/advisories/openclaw-strictinlineeval-approval-boundary-bypass-via-approval-timeout-fallback.
Details
- CWE(s)