Buffer overflow in Amartin755 Libsmi
CVE-2026-111137
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.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- hackmd.io/@haind-pwn/libsmi-smivalueasstring-octetstring-defval-oob-write (technical-description, exploit)
- github.com/amartin755/libsmi/blob/c58307210fe995ec419db976eb234aebc71a9216/lib/… (technical-description)
- github.com/amartin755/libsmi (product)
- www.vulncheck.com/advisories/libsmi-through-0.5.0-out-of-bounds-write-via-smiva… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111137?
- CVE-2026-111137 is a medium-severity vulnerability in Amartin755 Libsmi, classified under Out-of-bounds Write. CVSS score: 6.1/10. Published 2026-10-15.
- How severe is CVE-2026-111137?
- Medium severity. CVSS v3 base score is 6.1 out of 10.