What’s Vulnerable › Vulnerabilities

CVE-2026-111137: libsmi through 0.5.0 Out-of-Bounds Write via smiValueAsString OCTET STRING DEFVAL

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-15 · updated 2026-10-16
• Weakness: CWE-787

Description

libsmi through 0.5.0 contains an out-of-bounds write vulnerability in smiValueAsString() in lib/smi.c that allows attackers to overflow a fixed 1024-byte static buffer through hex rendering of OCTET STRING values. Attackers can supply a crafted MIB with an OCTET STRING DEFVAL of 512 or more octets and a leading 0x00 byte to corrupt adjacent library globals and crash smidump or other consumers.

Affected products

• amartin755 libsmi: through 0.5.0

References

• https://github.com/amartin755/libsmi
• https://github.com/amartin755/libsmi/blob/c58307210fe995ec419db976eb234aebc71a9216/lib/smi.c#L479-L566
• https://hackmd.io/@haind-pwn/libsmi-smivalueasstring-octetstring-defval-oob-write
• https://www.vulncheck.com/advisories/libsmi-through-0.5.0-out-of-bounds-write-via-smivalueasstring-octet-string-defval

Get alerted when CVE-2026-111137 or the next vulnerability affects your stack