CVE-2026-110714
libsmb2 through 6.2 contains an integer underflow vulnerability in decode_acl that allows malicious SMB servers to trigger heap out-of-bounds reads via crafted security descriptors.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
libsmb2 through 6.2 contains an integer underflow vulnerability in decode_acl 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 QUERY_INFO reply, bypassing ACE bounds checks and crashing the client.
- CVSS 4.0
- 7.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.54% probability · 45th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-191
- Source
- disclosure@vulncheck.com
EPSS moved from 0.5% on 15 October 2026 to 0.5% on 26 October 2026.
References
- https://github.com/sahlberg/libsmb2
- https://github.com/sahlberg/libsmb2/blob/d67e213a5c4e7e4969fd81f0b95e4ca5831fbba1/lib/smb2-data-security-descriptor.c#L266
- https://github.com/sahlberg/libsmb2/commit/523abe20be3207011a936db47f1d3bab79c05450
- https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read
- https://www.vulncheck.com/advisories/libsmb2-through-6.2-heap-out-of-bounds-read-via-decode-acl-integer-underflow
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.