CVE-2026-111280

high

Description

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.

References

https://www.vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-tsnap7microclient-opreadarea

https://github.com/davenardella/snap7/issues/31

https://github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_micro_client.cpp#L136-L150

https://github.com/davenardella/snap7

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-102471

Details

Source: Mitre, NVD

Published: 2026-10-15

Updated: 2026-10-16

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:C/A:C

Severity: High

CVSS v3

Base Score: 7.4

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H

Severity: High

CVSS v4

Base Score: 8.3

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00425