CVE-2025-57632 Affecting libsmb2 package, versions <6.2+dfsg-3
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published27 Sept 2025
- disclosed25 Sept 2025
Introduced: 25 Sep 2025
CVE-2025-57632 (opens in a new tab)How to fix?
Upgrade Debian:unstable libsmb2 to version 6.2+dfsg-3 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream libsmb2 package and not the libsmb2 package as distributed by Debian.
See How to fix? for Debian:unstable relevant fixed versions and status.
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://security-tracker.debian.org/tracker/CVE-2025-57632
- 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