Critical 9.8Published Apr 13, 2026

CVE-2026-31414netfilter: nf_conntrack_expect: use expect->helper

Updated under an hour ago (Oct 27, 2026, 7:00 PM ET)

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It affects Linux and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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 the skb.

CVSS: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-476
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before 847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781; from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before e7ccaa0a62a8ff2be5d521299ce79390c318d306; from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before 4bd1b3d839172724b33d8d02c5a4ff6a1c775417; from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before b53294bff19e56ada2f230ceb8b1ffde61cc3817; from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before 3dfd3f7712b5a800f2ba632179e9b738076a51f0; from ea781f197d6a835cbb93a0bf88ee1696296ed8aa before f01794106042ee27e54af6fdf5b319a2fe3df94d	CNA record
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 2.6.30 before 6.1.168; from 6.2 before 6.6.134; from 6.7 before 6.12.81; from 6.13 before 6.18.22; from 6.19 before 6.19.12; 7.0; 7.0; 7.0; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/847cb7fe26c5ce5dce0d1a41fac1ea488b7f1781	patch
https://git.kernel.org/stable/c/e7ccaa0a62a8ff2be5d521299ce79390c318d306	patch
https://git.kernel.org/stable/c/4bd1b3d839172724b33d8d02c5a4ff6a1c775417	patch
https://git.kernel.org/stable/c/b53294bff19e56ada2f230ceb8b1ffde61cc3817	patch
https://git.kernel.org/stable/c/3dfd3f7712b5a800f2ba632179e9b738076a51f0	patch
https://git.kernel.org/stable/c/f01794106042ee27e54af6fdf5b319a2fe3df94d	patch
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
https://cert-portal.siemens.com/productcert/html/ssa-457936.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.