Cyber Resilience

CVE-2026-35623

MediumPublic PoC

Published: 09 April 2026

Published
09 April 2026
Modified
16 April 2026
KEV Added
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Patch
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CVSS Score v4 6.3 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0011 28.5th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-35623 is a medium-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Openclaw Openclaw. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Brute Force (T1110); ranked at the 28.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

OpenClaw before 2026.3.25 contains a missing rate limiting vulnerability in webhook authentication that allows attackers to brute-force weak webhook passwords without throttling. Remote attackers can repeatedly submit incorrect password guesses to the webhook endpoint to compromise authentication and gain unauthorized…

more

access.

CWE(s)
CWE-307

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1110 Brute Force Credential Access
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained.
attack.mitre.org →
T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
attack.mitre.org →
Why these techniques?

Missing rate limiting on webhook auth directly enables repeated password guessing (brute force) against external service credentials.

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

Affected Assets

openclaw
openclaw
≤ 2026.3.25

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-7 Unsuccessful Logon Attempts
addresses: CWE-307

This control directly enforces limits on consecutive invalid logon attempts and automatic response (e.g., lockout) to prevent brute-force exploitation of authentication mechanisms.

IA-10 Adaptive Authentication
addresses: CWE-307

Specific conditions can include excessive failed attempts, triggering stronger authentication that restricts brute-force exploitation.

References