Review reviewCritical

CVE-2026-31414

Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: use expect->helper Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to...

CVSS
9.8
EPSS
0.40%
32.7% percentile
CISA KEV
Not listed
Published
2026.04.13
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.40%
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_expect: use expect->helper Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to...

Affected product and versions

Product
Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Affected versions
>= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781, >= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < e7ccaa0a62a8ff2be5d521299ce79390c318d306, >= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < 4bd1b3d839172724b33d8d02c5a4ff6a1c775417, >= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < b53294bff19e56ada2f230ceb8b1ffde61cc3817, >= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < 3dfd3f7712b5a800f2ba632179e9b738076a51f0, >= ea781f197d6a835cbb93a0bf88ee1696296ed8aa < f01794106042ee27e54af6fdf5b319a2fe3df94d, >= 2.6.30, >= V3.1.6, >= V3.1.5, >= 2.6.30 < 6.1.168, >= 6.2 < 6.6.134, >= 6.7 < 6.12.81, >= 6.13 < 6.18.22, >= 6.19 < 6.19.12, 7.0
Fixed versions
6.1.168, 6.6.134, 6.12.81, 6.18.22, 6.19.12

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2026-31414 — Linux Linux, SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | SECUFOCUS NOW