CVE-2026-110714 Details
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.
A heap-based buffer overflow vulnerability has been identified in libsmb2 versions through 6.2. This vulnerability arises from an integer underflow in the AclSize field of crafted security descriptors, which allows malicious SMB servers to manipulate the size of the data being read. When a client processes a QUERY_INFO reply, the decoder fails to properly validate the AclSize, leading to out-of-bounds reads that can be exploited to crash the client. This issue can be triggered by intercepting unsigned SMB sessions or by controlling the SMB server that the client is communicating with.
Users can upgrade to libsmb2 version 6.2 or later, where this vulnerability has been fixed. The latest version can be downloaded from the official libsmb2 GitHub repository.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 14, 2026CISA-ADP
Assessed Oct 20, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/sahlberg/libsmb2 | [email protected] | ProductSource CodeVendor |
| https://github.com/sahlberg/libsmb2/blob/d67e213a5c4e7e4969fd81f0b95e4ca5831fbba1/lib/smb2-data-security-descriptor.c#L266 | [email protected] | Source CodeVendor |
| https://github.com/sahlberg/libsmb2/commit/523abe20be3207011a936db47f1d3bab79c05450 | [email protected] | Source CodeVendor |
| https://hackmd.io/@haind-pwn/libsmb2-query-info-reply-oob-read | [email protected] | BundleExploitTechnical Analysis |
| https://www.vulncheck.com/advisories/libsmb2-through-6.2-heap-out-of-bounds-read-via-decode-acl-integer-underflow | [email protected] | AdvisoryBundle |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-191 | Integer Underflow (Wrap or Wraparound) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| libsmb2 | <= 6.2 |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 20, 2026 | CVE Modified | CISA-ADP |
| Oct 14, 2026 | New CVE Received | [email protected] |