Vulnerability · Published Oct 14, 2026 · Assigned by VulnCheck
CVE-2026-110714libsmb2 through 6.2 Heap Out-of-Bounds Read via decode_acl Integer Underflow
Medium 6.5
In plain English
A medium-severity security flaw in libsmb2 from sahlberg. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.5%top 54.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | libsmb2 | no fix listed | DEBIAN-CVE-2026-110714 |
| Debian:14 | libsmb2 | no fix listed | DEBIAN-CVE-2026-110714 |
| Ubuntu:26.04:LTS | libsmb2 | no fix listed | UBUNTU-CVE-2026-110714 |
| Ubuntu:26.10 | libsmb2 | no fix listed | UBUNTU-CVE-2026-110714 |
Affected products (as reported)
Weakness: CWE-191 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
- https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read technical-description, exploit
- https://github.com/sahlberg/libsmb2/blob/d67e213a5c4e7e4969fd81f0b95e4ca5831fbba1/lib/smb2-data-security-descriptor.c#L266 technical-description
- https://github.com/sahlberg/libsmb2/commit/523abe20be3207011a936db47f1d3bab79c05450 patch
- https://github.com/sahlberg/libsmb2 product
- VulnCheck Advisory: libsmb2 through 6.2 Heap Out-of-Bounds Read via decode_acl Integer Underflow third-party-advisory