CVE-2025-57632 Memory corruption in n/a
A buffer overflow in libsmb2 allows attackers to execute arbitrary code or cause denial of service via crafted SMB2 chained PDUs.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-57632?
CVE-2025-57632 is a high-severity memory corruption vulnerability in n/a, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-120
Which versions are affected by CVE-2025-57632?
How do I fix CVE-2025-57632?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-57632 being exploited?
There is no known exploitation of CVE-2025-57632 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2025-57632, GHSA-h8w6-x833-p4x4, UBUNTU-CVE-2025-57632.