{"id":"CVE-2026-85440","title":"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","summary":"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 …","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-787"],"vendor":"themoos","product":"core-moos","affected":["core-moos < 10.4.0"],"patched":["core-moos 10.4.0"],"published":"2026-09-03","updated":"2026-10-14","sourceUpdated":"2026-10-14T23:29:36.057","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-85440","references":[{"url":"https://github.com/themoos/core-moos","label":"disclosure@vulncheck.com"},{"url":"https://github.com/themoos/core-moos/blob/ec9c77c68fcbdef8f5e4c60fe243acd223433f0c/Core/libMOOS/Comms/MOOSCommPkt.cpp#L67","label":"disclosure@vulncheck.com"},{"url":"https://github.com/themoos/core-moos/commit/96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a","label":"disclosure@vulncheck.com"},{"url":"https://github.com/themoos/core-moos/pull/82","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/moos-core-moos-through-10.4.0-moosdb-pre-authentication-heap-overflow-via-negative-packet-length","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"epss":0.01026,"epssPercentile":0.63428,"ingestedAt":"2026-09-08T20:10:03.161Z","slug":"CVE-2026-85440","body":"## Overview\n\nMOOS 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.\n\n## Affected\n\n- `core-moos < 10.4.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `core-moos 10.4.0`","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.2,"exploitation":0,"ransomware":0},"changes":[]}