CVE-2026-110714

libsmb2 through 6.2 Heap Out-of-Bounds Read via decode_acl Integer Underflow

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.

Affected

sahlberg · libsmb2

CVSS v4.0 VULNCHECK

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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 VULNCHECK

6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS

0.55% chance of exploitation in the next 30 days, 45th percentile

Published

2026-10-14

Proof-of-concept exploits (1)

• https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read

References

• CVE Record
• NVD entry