# CVE-2026-54575: MidnightBSD mport time-of-check/time-of-use in package fetch and cleanup

Source: https://junglewise.ai/threats/cve-2026-54575-midnightbsd-mport-time-of-check-time-of-use-in-package-fetch-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-54575 · Severity: info · Published 2026-09-17

mport is the package manager for MidnightBSD, responsible for downloading, installing, and managing software packages. Prior to version 2.7.8, a local attacker with write access to package cache directories could exploit race conditions to redirect package downloads or bypass integrity checks, potentially allowing installation of malicious software or unauthorized modification of the system.

Technologies: [MidnightBSD Mport](https://junglewise.ai/threats/technologies/mport). Vendors: [MidnightBSD](https://junglewise.ai/threats/vendors/midnightbsd).

## Quick answers

**Is CVE-2026-54575 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54575 being exploited in the wild.

**How severe is CVE-2026-54575?** Informational severity, published 17 September 2026.

**Which products and versions are affected?** MidnightBSD Mport prior to 2.7.8.

**Is there a fix for CVE-2026-54575?** A patch was published on 2026-04-23: Security fix merged in commit 29154b0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54575 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-54575?** Check whether you run MidnightBSD Mport at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a time-of-check/time-of-use (TOCTOU) race condition affecting privileged package fetch and cache-cleaning operations across multiple components (libmport/fetch.c, libmport/clean.c, libmport/util.c, and others). The vulnerable code performed path validation and file operations non-atomically, allowing a local attacker with write access to package cache or staging directories to race checks and replacement operations. Additionally, the affected lifecycle helper paths used shell-form invocation during privileged helper execution, increasing command-line interpretation risk. The issue is fixed in version 2.7.8 by validating filenames, using directory file descriptors for race-resistant operations, and replacing shell hooks with safer execution methods.

## Affected products

- MidnightBSD mport prior to 2.7.8

## Timeline

- 2026-04-23: patched: Security fix merged in commit 29154b0
- 2026-09-17: disclosed

## References

- [https://github.com/MidnightBSD/mport/commit/29154b0fdfb5806568ed1277e88d942bad6d1169](https://github.com/MidnightBSD/mport/commit/29154b0fdfb5806568ed1277e88d942bad6d1169)
- [https://github.com/MidnightBSD/mport/pull/118](https://github.com/MidnightBSD/mport/pull/118)

## Related threats

- [mport insecure TMPDIR usage in privileged contexts](https://junglewise.ai/threats/cve-2026-54584-mport-is-the-midnightbsd-package-manager-mport-before-2-7-8-used)
- [MidnightBSD mport directory traversal in package installation](https://junglewise.ai/threats/cve-2026-54587-midnightbsd-mport-directory-traversal-in-package-installation)
- [MidnightBSD mport HTTP package fetch without HTTPS enforcement](https://junglewise.ai/threats/cve-2026-54586-midnightbsd-mport-http-package-fetch-without-https-enforcement)
- [MidnightBSD mport path traversal in sample-file handling](https://junglewise.ai/threats/cve-2026-54585-midnightbsd-mport-path-traversal-in-sample-file-handling)
- [MidnightBSD mport path traversal in bundle filename handling](https://junglewise.ai/threats/cve-2026-54583-midnightbsd-mport-path-traversal-in-bundle-filename-handling)