# CVE-2026-54581: mport bootstrap index fetch can continue after hash verification failure

> Attackers can bypass hash verification in MidnightBSD's mport, allowing tampered package indexes to be processed, potentially leading to code execution.

- **Severity:** High 8.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-895r-rv8j-7g23

## What is CVE-2026-54581?

CVE-2026-54581 is a high-severity vulnerability in MidnightBSD mport, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

mport is the MidnightBSD Package Manager. Prior to 2.7.8, the mport_fetch_bootstrap_index() function in libmport/fetch.c could return success when bootstrap index hash verification encountered a missing or invalid hash because the failure path did not preserve a fatal result. A network attacker or compromised mirror able to alter bootstrap index content or its transport path could therefore cause mport to proceed with an unverified or tampered bootstrap package index. This issue is fixed in version 2.7.8.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature), CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-54581?


## How do I fix CVE-2026-54581?

No fix has been published for CVE-2026-54581 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-54581 being exploited?

There is no known exploitation of CVE-2026-54581 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-54581 and fix it if it is affected.

What it is: CVE-2026-54581 is a high-severity vulnerability in MidnightBSD mport, published on 17 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-54581 in the wild and no public exploit code.

Affected product: MidnightBSD mport. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-54581/ (Markdown: https://insights.sbomify.com/CVE-2026-54581/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-54581
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-54581
- OSV: https://osv.dev/vulnerability/CVE-2026-54581

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-54581/
Summaries are generated and may contain mistakes; the official description above is the record.