CVE-2026-85440: Out-of-bounds Write in themoos core-moos
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.
CVSS v4.0
Score 9.3critical
Affected software
themoos
core-moos
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-85440 is a pre-authentication heap overflow vulnerability in MOOS core-moos (up to version 10.4.0) within the MOOSCommPkt packet handling component. The vulnerability arises from improper handling of a negative packet length, which leads to a signed integer check bypass in InflateTo() and a negative size conversion in recv(). This results in an overflow of a four-byte heap buffer during the handshake phase before authentication, enabling remote attackers to write arbitrary data.
Potential Impact
The vulnerability allows unauthenticated remote attackers to perform a heap overflow, potentially leading to arbitrary code execution or denial of service. Given the critical CVSS score of 9.3 and the ability to exploit this before authentication, the impact is severe. No known exploits in the wild have been reported yet.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround has been documented at this time.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-09-03T19:50:57.793Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a99fa4aacd9273b4994b230
Added to database: 09/03/2026, 22:52:58 UTC
Last enriched: 09/07/2026, 12:07:11 UTC
Last updated: 10/17/2026, 06:48:21 UTC
Views: 64
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