Buffer overflow in Davenardella Snap7
CVE-2026-111280
snap7 through 1.4.3 contains an out-of-bounds write vulnerability in TSnap7MicroClient::opReadArea() that allows malicious S7 peers to overflow client buffers via an unchecked DataLength field. Rogue or impersonated PLCs can return crafted ReadVar responses causing memcpy of up to 65535 bytes into caller buffers, crashing SCADA, HMI, or gateway processes and corrupting memory.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/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
- github.com/davenardella/snap7/issues/31 (issue-tracking)
- github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src… (technical-description)
- github.com/davenardella/snap7 (product)
- www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-tsnap7… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-111280?
- CVE-2026-111280 is a high-severity vulnerability in Davenardella Snap7, classified under Out-of-bounds Write. CVSS score: 7.4/10. Published 2026-10-15.
- How severe is CVE-2026-111280?
- High severity. CVSS v3 base score is 7.4 out of 10.