# CVE-2026-5474: NASA cFS CCSDS Packet Header to_lab_passthru_encode.c CFE_MSG_GetSize heap-based overflow

> A heap-based buffer overflow in NASA cFS allows local network attackers to execute arbitrary code or cause denial of service via crafted CCSDS packets.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Apr 2026
- **Updated:** 3 Apr 2026
- **Also known as:** GHSA-43rr-mfcw-532v

## What is CVE-2026-5474?

CVE-2026-5474 is a medium-severity memory corruption vulnerability in NASA cFS, published on 3 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was found in NASA cFS up to 7.0.0. This affects the function CFE_MSG_GetSize of the file apps/to_lab/fsw/src/to_lab_passthru_encode.c of the component CCSDS Packet Header Handler. Performing a manipulation results in heap-based buffer overflow. The attacker must have access to the local network to execute the attack. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-122 (Heap-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-5474?

It affects 1 product.


Products: Nasa Core Flight System.

## How do I fix CVE-2026-5474?

No fix has been published for CVE-2026-5474 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5474 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5474 exists.

## Other vulnerabilities in NASA cFS

- [CVE-2025-25373](https://insights.sbomify.com/CVE-2025-25373/): Missing authorization in n/a (critical 9.8)
- [CVE-2025-25371](https://insights.sbomify.com/CVE-2025-25371/): Path traversal in n/a (high 7.5)
- [CVE-2025-25372](https://insights.sbomify.com/CVE-2025-25372/): Memory corruption in n/a (high 7.5)
- [CVE-2025-25374](https://insights.sbomify.com/CVE-2025-25374/): Denial of service in n/a (high 7.5)
- [CVE-2026-5475](https://insights.sbomify.com/CVE-2026-5475/): NASA cFS CCSDS Header Size cfe_sb_priv.c CFE_SB_TransmitMsg memory corruption (medium 5.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5474 and fix it if it is affected.

What it is: CVE-2026-5474 is a medium-severity memory corruption vulnerability in NASA cFS, published on 3 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-5474 exists.

Affected product: NASA cFS. 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-2026-5474/ (Markdown: https://insights.sbomify.com/CVE-2026-5474/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5474
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5474
- OSV: https://osv.dev/vulnerability/CVE-2026-5474

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-5474/
Summaries are generated and may contain mistakes; the official description above is the record.