# CVE-2026-54578: MidnightBSD mport checksum verification bypass

Source: https://junglewise.ai/threats/cve-2026-54578-midnightbsd-mport-checksum-verification-bypass  
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-2026-54578 · Severity: info · Published 2026-09-17

mport is the package manager for MidnightBSD, responsible for installing and verifying the integrity of software packages. Prior to version 2.7.8, a flaw in the package verification logic could allow attackers to bypass checksum validation by causing hash computation failures, resulting in misleading integrity checks that hide tampered or corrupted files.

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

## Quick answers

**Is CVE-2026-54578 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-54578 being exploited in the wild.

**How severe is CVE-2026-54578?** 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-2026-54578?** A patch was published on 2026-05-19: Fix committed to main branch Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-54578 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-54578?** 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 logic error in mport_verify_package() within libmport/verify.c where the function could continue execution and compare checksums against stale data in the hash buffer after MD5File() or SHA256_File() failed. The root cause is improper error handling that does not skip asset verification when hashing fails, allowing an attacker to influence installed files or hashing conditions to either receive misleading integrity results or hide checksum failures entirely. Attack vector is local with no authentication required. The fix in version 2.7.8 wraps verification in proper transaction handling and corrects control flow to skip assets when hashing fails, ensuring only valid computed digests are compared.

## Affected products

- MidnightBSD mport prior to 2.7.8

## Timeline

- 2026-09-17: disclosed
- 2026-05-19: patched: Fix committed to main branch

## References

- [https://github.com/MidnightBSD/mport/commit/cd9991c3cc1f60ecb3f378852ad8b5caa820e990](https://github.com/MidnightBSD/mport/commit/cd9991c3cc1f60ecb3f378852ad8b5caa820e990)
- [https://github.com/MidnightBSD/mport/pull/138](https://github.com/MidnightBSD/mport/pull/138)

## 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)