Integer Overflow Vulnerability in libsmb2 Affects Samba Client
CVE-2026-115505

7.2HIGH

Key Information:

Vendor

Sahlberg

Status
Libsmb2
Vendor
CVE Published:
22 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-115505?

The libsmb2 library prior to version 6.3 contains integer overflow vulnerabilities in the DCE/RPC NDR decoder, specifically in the lib/dcerpc.c file. Exploiting these vulnerabilities, an attacker can craft malicious NetrShareEnum replies through an unauthorized SMB server or machine-in-the-middle on unsigned connections. This manipulation can lead to heap out-of-bounds reads and writes, potentially resulting in memory corruption and unauthorized access to sensitive data. Proper measures should be taken to upgrade to the latest version to mitigate these risks.

Affected Version(s)

libsmb2 0 < 6.3

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-115505 - Proof of Concept

References

https://hackmd.io/@haindpwn/libsmb2-dcerpc-ndr-count-over...
technical-descriptionexploit
https://github.com/sahlberg/libsmb2/issues/496
issue-tracking
https://github.com/sahlberg/libsmb2/commit/a79f6914cb5ed3...
patch

CVSS V4

Score:
7.2
Severity:
HIGH
Confidentiality:
Low
Integrity:
Low
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

HaiND from the Post and Telecommunication Institute of Technology
.