{"id":"CVE-2026-55200","revision":"c6448ce7a24f43a6a79ee1d0dc4f7b1a","records":[{"revision":"c6448ce7a24f43a6a79ee1d0dc4f7b1a","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-55200","aliases":[],"title":"libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c","description":"libssh2 1.11.1, fixed in commit 97acf3d, contains an out-of-bounds write vulnerability in ssh2_transport_read() that fails to enforce upper bounds on packet_length field. Remote attackers can send crafted SSH packets with excessively large packet_length values to corrupt heap memory and achieve remote code execution.","state":0,"publishedAt":"2026-06-17T19:03:15.183+00:00","modifiedAt":"2026-10-22T18:33:35.066+00:00","affected":[{"ecosystem":"Vendor product","name":"libssh2","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"libssh2\",\n                    \"product\": \"libssh2\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:github/libssh2/libssh2\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"1.11.1\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"1c3f1b7da588f2652260285529ec3c1f1125eb4e\",\n                            \"versionType\": \"git\",\n                            \"lessThan\": \"97acf3dfda80c91c3a8c9f2372546301d4a1a7a8\"\n                        }\n                    ],\n                    \"repo\": \"https://github.com/libssh2/libssh2\"\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":9.2,"severity":"CRITICAL"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.1,"severity":"HIGH"}],"references":["https://github.com/libssh2/libssh2/pull/2052","https://github.com/libssh2/libssh2/commit/97acf3dfda80c91c3a8c9f2372546301d4a1a7a8","https://www.vulncheck.com/advisories/libssh2-out-of-bounds-write-via-unchecked-packet-length-in-transport-c"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-55200","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-55200","identifiers":["CVE-2026-55200"]},"retained":false,"historicalAffected":[]}],"coverage":[]}