ClearanceKit CVE-2026-40599

Exploitation requires the attacker to have an existing local user account on the target macOS system running vulnerable ClearanceKit versions (prior to 5.0.5). The attacker must be able to execute arbitrary binaries on the system, which requires either uploading a crafted executable or compiling malicious code locally. No administrator privileges are needed (PR:L in CVSS vector) - standard user account access suffices. ClearanceKit must be actively deployed and enforcing file-access policies on the target system, with sensitive files protected by allowlist rules that include Apple platform binaries. Exploitation is limited to macOS platforms as ClearanceKit is macOS-specific. The vulnerability affects default ClearanceKit configurations with no special deployment mode required. Attack complexity is low (AC:L) as creating a binary with empty Team ID is trivial - unsigned binaries or ad-hoc signed code naturally meet this condition. No user interaction required (UI:N) once the malicious process executes.

Real-world risk is significant for environments relying on ClearanceKit for data protection, though exploitation scope is constrained by local access requirements. CVSS:4.0 vector (AV:L/AC:L/PR:L) indicates low-complexity local exploitation requiring only low-privilege user account access - no administrator rights needed. High confidentiality and integrity impact (VC:H/VI:H) with zero availability impact (VA:N) reflects ability to read and modify protected files without disrupting system operations. EPSS score unavailable; no CISA KEV listing suggests targeted rather than widespread exploitation. The GitHub security advisory (GHSA-w253-42qp-5f2x) provides vendor confirmation and fix version, reducing uncertainty. Primary risk factors: (1) trivial exploit complexity once local access obtained, (2) complete bypass of ClearanceKit's protection model, (3) stealth potential as malicious process appears legitimate in logs. Mitigating factors: (1) requires prior foothold on target system, (2) limited to macOS environments running vulnerable ClearanceKit versions, (3) patch available with clear upgrade path. Priority level depends on ClearanceKit deployment scale and sensitivity of protected data - critical for enterprises using ClearanceKit to secure intellectual property or compliance-regulated files, moderate for hobbyist deployments.

An attacker gains local user access to a macOS system running ClearanceKit 5.0.4 through phishing, stolen credentials, or supply-chain compromise. The attacker crafts a malicious executable with an empty Team ID and arbitrary Signing ID using standard macOS code signing tools or by leaving the binary unsigned. When executed, ClearanceKit's flawed validation treats this process as a trusted Apple platform binary, granting it access to files protected by ClearanceKit policies - such as financial records, source code repositories, or customer databases. The attacker exfiltrates sensitive data or modifies configuration files to establish persistence, all while appearing in system logs as a legitimate Apple process. No public exploit code confirmed, but the vulnerability's simplicity (basic code signing manipulation) makes proof-of-concept development straightforward for attackers with macOS development knowledge.