{"id":"UBUNTU-CVE-2025-57632","details":"libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2_add_iovector() to append to a fixed-size iovec array without checking the upper bound of v-\u003eniov (SMB2_MAX_VECTORS=256). An attacker can craft responses with many chained PDUs to overflow v-\u003eniov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2_OPLOCK_BREAK path bypasses message ID validation.","modified":"2026-05-20T16:23:36.375485301Z","published":"2025-09-25T20:15:00Z","upstream":["CVE-2025-57632"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2025-57632"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2025-57632"},{"type":"REPORT","url":"https://gist.github.com/ZjW1nd/0b95b63307ceee7890e88e4abc6f041e"},{"type":"REPORT","url":"https://github.com/sahlberg/libsmb2"},{"type":"REPORT","url":"https://github.com/sahlberg/libsmb2/blob/master/lib/compat.c#L569"}],"affected":[{"package":{"name":"libsmb2","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/libsmb2?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.2+dfsg-2"],"ecosystem_specific":{"binaries":[{"binary_name":"libsmb2-6","binary_version":"6.2+dfsg-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-57632.json"}},{"package":{"name":"libsmb2","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/libsmb2?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.2+dfsg-2","6.2+dfsg-3"],"ecosystem_specific":{"binaries":[{"binary_version":"6.2+dfsg-3","binary_name":"libsmb2-6"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2025/UBUNTU-CVE-2025-57632.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}