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CRITICAL

CVE-2026-85440

CVSS v3

9.8

CRITICAL

EPSS Score

1.0 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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.

Technical details

Published
2026-09-03
Last Modified
2026-09-04

Frequently asked questions

What is CVE-2026-85440?

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.

Is CVE-2026-85440 actively exploited?

Active exploitation of CVE-2026-85440 has not been confirmed. Its EPSS score was 1.0% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-85440?

CVE-2026-85440 has a CVSS v3 base score of 9.8 (CRITICAL severity).

Is CVE-2026-85440 affecting your environment?

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