{"id":"CVE-2026-115723","title":"Snap7 through 1.4.3 Out-of-Bounds Write via BRecv and CheckAsBRecvCompletion","summary":"Snap7 through 1.4.3 contains an out-of-bounds write vulnerability in the passive partner that allows a malicious active partner to overflow application buffers by declaring an unvalidated BSend total length. Attackers connecting from the…","severity":"high","cvss":7.4,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"davenardella","product":"snap7","affected":["snap7 <= 1.4.3"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-23T14:48:43.225515Z"},"published":"2026-10-23","updated":"2026-10-23","sourceUpdated":"2026-10-23T14:59:52.690Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115723","references":[{"url":"https://github.com/davenardella/snap7/pull/41"},{"url":"https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L1126-L1166"},{"url":"https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L850-L867"},{"url":"https://www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-brecv-and-checkasbrecvcompletion","label":"VulnCheck Advisory: Snap7 through 1.4.3 Out-of-Bounds Write via BRecv and CheckAsBRecvCompletion"}],"tags":["cve.org"],"ingestedAt":"2026-10-23T13:24:55.587Z","slug":"CVE-2026-115723","body":"## Overview\n\nSnap7 through 1.4.3 contains an out-of-bounds write vulnerability in the passive partner that allows a malicious active partner to overflow application buffers by declaring an unvalidated BSend total length. Attackers connecting from the configured peer address can declare up to 65535 bytes and send a short fragment, causing BRecv to memcpy past the buffer and crash or corrupt SCADA, HMI or gateway processes.\n\n## Affected\n\n- `snap7 <= 1.4.3`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":40.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}