CVE-2026-40604
Published: 21 April 2026
Summary
CVE-2026-40604 is a high-severity Protection Mechanism Failure (CWE-693) vulnerability in Craigjbass Clearancekit. Its CVSS base score is 8.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Disable or Modify Tools (T1685); ranked at the 1.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-24213
Vulnerability details
ClearanceKit intercepts file-system access events on macOS and enforces per-process access policies. Prior to 5.0.6, the opfilter Endpoint Security system extension (bundle ID uk.craigbass.clearancekit.opfilter) can be suspended with SIGSTOP or kill -STOP, or killed with SIGKILL/SIGTERM, by any process running…
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as root. While the extension is suspended, all AUTH Endpoint Security events time out and default to allow, silently disabling ClearanceKit's file-access policy enforcement for the duration of the suspension. This vulnerability is fixed in 5.0.6.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Root attacker can directly suspend/kill the Endpoint Security extension, disabling policy enforcement (maps to impairing/defeating security tools).
Affected Assets
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.
Implements a reliable, tamperproof protection mechanism whose completeness can be assured.
Procedures for training on protection mechanisms reduce the chance of protection mechanism failures being present or exploitable.
Documented procedures to implement assessment, authorization, and monitoring controls prevent these protection mechanisms from failing due to undefined processes.
Direct evaluation of whether controls produce desired security outcomes detects protection mechanism failures and enables remediation.
Requires assessment that protection mechanisms are correctly implemented and producing intended security outcomes.
The POA&M process ensures identified weaknesses in protection mechanisms are documented and scheduled for remediation, reducing the duration they remain exploitable.
Ongoing control assessments and analysis of monitoring data enable timely detection and response when protection mechanisms fail.
Impact analysis identifies changes that could weaken or disable existing protection mechanisms.