libsmb2 6.2+ is vulnerable to Buffer Overflow. When processing SMB2 chained PDUs (NextCommand), libsmb2 repeatedly calls smb2addiovector() to append to a fixed-size iovec array without checking the upper bound of v->niov (SMB2MAXVECTORS=256). An attacker can craft responses with many chained PDUs to overflow v->niov and perform heap out-of-bounds writes, causing memory corruption, crashes, and potentially arbitrary code execution. The SMB2OPLOCKBREAK path bypasses message ID validation.

libsmb2 through 6.2 contains an integer underflow vulnerability in decodeacl that allows malicious SMB servers to trigger heap out-of-bounds reads via crafted security descriptors. Attackers controlling a server or intercepting unsigned sessions can send an AclSize below 8 in a QUERYINFO reply, bypassing ACE bounds checks and crashing the client.

libsmb2 through 6.2 contains a heap out-of-bounds read vulnerability in smb2decodefilefsvolumeinfo and smb2decodefilefsattributeinfo that allows malicious SMB servers to read past reply buffers. Attackers controlling a server or intercepting unsigned sessions can send crafted QUERYINFO replies with missing or oversized name lengths to crash the client.