← All Advisories

CVE-2026-23456

Last refreshed2026-10-06

Status: UPDATED  |  Advisory ID: CVE-2026-23456

Key Details

CVECVE-2026-23456
CVSS Score / Version8.2 (High) / CVSS v3.1
Updated2026-07-24
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
CVSS Proseattack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is unchanged; confidentiality impact is low; integrity impact is none; availability impact is high.
Affected productsSiemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, and Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classified asCWE-125 (Out-of-bounds Read)

Affected Products, Subsystems & Sectors

VendorProductAffected VersionsPatch Status
SiemensSIMATIC S7-1500 CPU 1518-4 PN/DP MFP
SiemensSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
SiemensSIPLUS S7-1500 CPU 1518-4 PN/DP MFP
SubsystemsGeneral OT
SectorsMultiple

What to Know

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_conntrack_h323: fix OOB read in decode_int() CONS case

In decode_int(), the CONS case calls get_bits(bs, 2) to read a length

value, then calls get_uint(bs, len) without checking that len bytes

remain in the buffer. The existing boundary check only validates the

2 bits for get_bits(), not the subsequent 1-4 bytes that get_uint()

reads. This allows a malformed H.323/RAS packet to cause a 1-4 byte

slab-out-of-bounds read.

Add a boundary check for len bytes after get_bits() and before

get_uint(). (NVD)

What to Do

Monitor Siemens's web page for any future patch releases.

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-23456
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-23456