Out-of-Bounds Write Vulnerability in libsmi by Open Source Developer
CVE-2026-111137

6.9MEDIUM

Key Information:

Vendor

Amartin755

Status
Libsmi
Vendor
CVE Published:
15 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-111137?

The libsmi library, up to version 0.5.0, contains a critical out-of-bounds write vulnerability in the smiValueAsString() function located in lib/smi.c. This flaw allows attackers to exploit a fixed 1024-byte buffer. By supplying a maliciously crafted Management Information Base (MIB) that includes an OCTET STRING DEFVAL with 512 or more octets alongside a leading 0x00 byte, an attacker can overwrite adjacent memory used by library globals. This can lead to potential crashes of applications such as smidump and may expose systems to additional risks.

Affected Version(s)

libsmi 0 <= 0.5.0

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-2026-111137 - Proof of Concept

References

https://hackmd.io/@haind-pwn/libsmi-smivalueasstring-octe...
technical-descriptionexploit
https://github.com/amartin755/libsmi/blob/c58307210fe995e...
technical-description
https://github.com/amartin755/libsmi
product

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
High
Attack Vector:
Local
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
.