CVE-2026-111280 snap7 - Buffer Overflow

snap7 through 1.4.3 contains a buffer overflow caused by unchecked DataLength field in TSnap7MicroClient::opReadArea(), letting malicious S7 peers crash processes and corrupt memory, exploit requires crafted ReadVar responses from rogue or impersonated PLCs.

CVSS base score 7.4 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
View the NVD record ↗

Details

Type
Out Of Bounds Rw
Impact
Denial Of Service, Undefined
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
Published
15 October 2026
Updated
16 October 2026
Weakness
CWE-787

Vendor fix

Update to the latest version beyond 1.4.3.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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