{"id":"UBUNTU-CVE-2026-115723","details":"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 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.","modified":"2026-10-28T17:50:38Z","published":"2026-10-23T12:18:00Z","upstream":["CVE-2026-115723"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-115723"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-115723"},{"type":"REPORT","url":"https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L1126-L1166"},{"type":"REPORT","url":"https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_partner.cpp#L850-L867"},{"type":"REPORT","url":"https://github.com/davenardella/snap7/pull/41"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-brecv-and-checkasbrecvcompletion"}],"affected":[{"package":{"name":"snap7","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/snap7?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.2+dfsg-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libsnap7-1","binary_version":"1.4.2+dfsg-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-115723.json"}},{"package":{"name":"snap7","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/snap7?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.2+dfsg-1","1.4.2+dfsg-1build1"],"ecosystem_specific":{"binaries":[{"binary_name":"libsnap7-1","binary_version":"1.4.2+dfsg-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-115723.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}