CVE-2026-111280
snap7 through 1.4.3 Out-of-Bounds Write via TSnap7MicroClient::opReadArea
davenardella snap7
CVSS
8.3HighExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 23 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.43%Chance of exploitation activity in the next 30 days, higher than 35% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
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.
Text from CVE List
Affected versions 1
- snap7affected: all versions through 1.4.3CVE List
References 4
- vulncheck.com/advisories/snap7-through-1.4.3-out-of-bounds-write-via-tsnap7microclient-opreadareaAdvisoryvia CVE List
- github.com/davenardella/snap7/issues/31Exploitvia CVE List
- github.com/davenardella/snap7/blob/30f37da3114024a71ba93f7fd855c680b97a406f/src/core/s7_micro_client.cpp#L136-L150Referencevia CVE List
- github.com/davenardella/snap7Referencevia CVE List