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

High 8.7 Published 3 Sep 2026 Updated 4 Sep 2026

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

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

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

Which versions are affected by CVE-2026-85436?

It affects 1 product.

Products include 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.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-85436 being exploited?

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

Sources

Also known as GHSA-fj6h-5wvf-8fj2.