# CVE-2026-85436: MOOS essential-moos through 10.0.1 pMOOSBridge Heap Corruption via Negative UDP Length

> Remote attackers can cause heap corruption and denial of service in MOOS essential-moos by sending crafted UDP packets with negative lengths.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:** 3 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** GHSA-fj6h-5wvf-8fj2

## What is CVE-2026-85436?

CVE-2026-85436 is a high-severity memory corruption vulnerability in themoos essential-moos, published on 3 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MOOS essential-moos through 10.0.1 contains a buffer overflow vulnerability in CMOOSUDPLink::ReadPktFromArray() that allows remote attackers to corrupt heap memory by sending UDP datagrams with negative declared lengths. Attackers can send crafted UDP packets to the configured UDPListen port to trigger an oversized memcpy operation that writes past the destination buffer, causing heap corruption and denial of service.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2026-85436?

It affects 1 product.


Products: Themoos Essential-Moos.

## How do I fix CVE-2026-85436?

No fix has been published for CVE-2026-85436 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-85436 being exploited?

There is no known exploitation of CVE-2026-85436 in the wild and no public exploit code.

## Other vulnerabilities in themoos essential-moos

- [CVE-2026-85433](https://insights.sbomify.com/CVE-2026-85433/): MOOS essential-moos through 10.0.1 pShare Unauthorized Runtime Route Reconfiguration (critical 9.3)
- [CVE-2026-85427](https://insights.sbomify.com/CVE-2026-85427/): MOOS essential-moos through 10.0.1 pAntler Remote Code Execution via Unauthenticated MISSION_FILE (critical 9.2)
- [CVE-2026-85430](https://insights.sbomify.com/CVE-2026-85430/): MOOS essential-moos through 10.0.1 pShare Unauthenticated UDP Datagram Republishing (high 8.8)
- [CVE-2026-85431](https://insights.sbomify.com/CVE-2026-85431/): MOOS essential-moos through 10.0.1 pMOOSBridge Unauthenticated UDP Packet Injection (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85436 and fix it if it is affected.

What it is: CVE-2026-85436 is a high-severity memory corruption vulnerability in themoos essential-moos, published on 3 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-2026-85436 in the wild and no public exploit code.

Affected product: themoos essential-moos. 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-2026-85436/ (Markdown: https://insights.sbomify.com/CVE-2026-85436/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85436
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85436
- OSV: https://osv.dev/vulnerability/CVE-2026-85436

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85436/
Summaries are generated and may contain mistakes; the official description above is the record.