9.8
CRITICAL CVSS 3.1
CVE-2026-85440
MOOS core-moos through 10.4.0 MOOSDB Pre-Authentication Heap Overflow via Negative Packet Length
Description

MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability in MOOSCommPkt packet handling that allows remote attackers to write arbitrary data by declaring a negative packet length. Attackers can exploit the signed integer check in InflateTo() and negative size conversion in recv() to overflow a four-byte heap buffer during the HandShake phase before authentication.

INFO

Published Date :

Sept. 3, 2026, 11:17 p.m.

Last Modified :

Sept. 3, 2026, 11:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-85440 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL [email protected]
Solution
Update MOOS core-moos to resolve heap overflow in packet handling.
  • Apply the latest security patch for MOOS core-moos.
  • Update MOOS core-moos to version 10.4.1 or later.
  • Ensure proper validation of packet lengths.
  • Review and harden packet handling code.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-85440 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-85440 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-85440 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-85440 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Sep. 03, 2026

    Action Type Old Value New Value
    Added Description MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability in MOOSCommPkt packet handling that allows remote attackers to write arbitrary data by declaring a negative packet length. Attackers can exploit the signed integer check in InflateTo() and negative size conversion in recv() to overflow a four-byte heap buffer during the HandShake phase before authentication.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-787
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/85xxx/CVE-2026-85440.json">CVE-2026-85440</a>
    Added Reference https://github.com/themoos/core-moos
    Added Reference https://github.com/themoos/core-moos/blob/ec9c77c68fcbdef8f5e4c60fe243acd223433f0c/Core/libMOOS/Comms/MOOSCommPkt.cpp#L67
    Added Reference https://github.com/themoos/core-moos/commit/96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a
    Added Reference https://github.com/themoos/core-moos/pull/82
    Added Reference https://www.vulncheck.com/advisories/moos-core-moos-through-10.4.0-moosdb-pre-authentication-heap-overflow-via-negative-packet-length
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.