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.
SeverityHigh
CVSS7.4
Exploit probability—
ProductDavenardella Snap7
PublishedOct 15, 2026
First seenOct 15, 2026
Weakness typeCWE-787Out-of-bounds write
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| davenardella snap7 | v ≤ 1.4.3 | — |
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