What’s Vulnerable › Vulnerabilities

CVE-2025-57632

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-09-25 · updated 2026-06-17
• Weakness: CWE-120

Description

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->niov (SMB2_MAX_VECTORS=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 SMB2_OPLOCK_BREAK path bypasses message ID validation.

References

• https://gist.github.com/ZjW1nd/0b95b63307ceee7890e88e4abc6f041e
• https://github.com/sahlberg/libsmb2
• https://github.com/sahlberg/libsmb2/blob/master/lib/compat.c#L569
• https://github.com/sahlberg/libsmb2/commit/5e75eebf922b338cdb548d60cffb3b997d2a12e8

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