High Access control

CVE-2026-33631 — ClearanceKit: opfilter policy bypass via non-open file operations

ClearanceKit intercepts file-system access events on macOS and enforces per-process access policies. In versions on the 4.1 branch and earlier, the opfilter Endpoint Security system extension enforced file access policy exclusively by intercepting ES_EVENT_TYPE_AUTH_OPEN events. Seven additional file operation event types were not intercepted, allowing any locally running process to bypass the configured FAA policy without triggering a denial. Commit a3d1733 adds subscriptions for all seven event types and routes them through the existing FAA policy evaluator. AUTH_RENAME and AUTH_UNLINK additionally preserve XProtect change detection: events on the XProtect path are allowed and trigger the existing onXProtectChanged callback rather than being evaluated against user policy. All versions on the 4.2 branch contain the fix. No known workarounds are available.

Published Mar 26, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (30-day exploitation probability)+1
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.15%

ahead of 3% of scored CVEs · Oct 14, 2026

Affects

Craigjbass

Clearancekit

CVSS base

8.7

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Craigjbass Clearancekit).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Craigjbass	Clearancekit	< 4.2	Vulnerable	NIST National Vulnerability Database
Craigjbass	Clearancekit	version < 4.2	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

Low

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.7	CVSS 3.1	High	2.0	6.0	security-advisories@github.com via NIST National Vulnerability Database
8.7	CVSS 3.1	High	—	—	GitHub_M via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-862 · Missing Authorization

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.15%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Audit administrative actions and access to resources outside each user’s normal pattern.

endpoint telemetry (EDR)authentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · craigjbass/clearancekit
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 8.7
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Mar 26, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

github.com/craigjbass/clearancekit/commit/a3d1733d2691a0d40209c48b01bf9291bf6452
Patch, x_refsource_MISC, NIST National Vulnerability Database
github.com/craigjbass/clearancekit/security/advisories/GHSA-25f8-8cj2-m887
Patch, Vendor Advisory, x_refsource_CONFIRM, NIST National Vulnerability Database

Elsewhere on this site

Craigjbass
every CVE for this vendor

Access control
same class

CWE-862
other pages naming this weakness

Related CVEs (same products)

Medium CVE-2026-47134 ClearanceKit: Policy signing key in System Keychain has permissive ACL allowing any local-root process to forge signed policy Jul 20, 2026
Medium CVE-2026-47133 ClearanceKit's signed policy tables lack monotonic counter, allowing replay of older legitimately-signed snapshots Jul 20, 2026
High CVE-2026-40599 ClearanceKit: Ad-hoc signed binaries can spoof Apple process identities in the global allowlist Apr 21, 2026
Medium CVE-2026-40604 ClearanceKit: opfilter system extension can be suspended or signalled by a root process, disabling file-access policy enforcement Apr 21, 2026
Medium CVE-2026-40191 ClearanceKit has a policy bypass via dual-path Endpoint Security events checking only source path Apr 10, 2026
Medium CVE-2026-34218 ClearanceKit: Managed and user-defined policy rules not enforced between opfilter start and first policy modification Mar 31, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-33631 is "ClearanceKit: opfilter policy bypass via non-open file operations", rated High. It affects Clearancekit (Craigjbass); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.7 describes technical severity. EPSS 0.15% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.