High 7.3Published May 1, 2026

CVE-2026-43025netfilter: ctnetlink: ignore explicit helper on new expectations

Updated under an hour ago (Oct 27, 2026, 11:40 AM 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: ctnetlink: ignore explicit helper on new expectations Use the existing master conntrack helper, anything else is not really supported and it just makes validation more complicated, so just ignore what helper userspace suggests for this expectation. This was uncovered when validating CTA_EXPECT_CLASS via different helper provided by userspace than the existing master conntrack helper: BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0 Read of size 4 at addr ffff8880043fe408 by task poc/102 Call Trace: nf_ct_expect_related_report+0x2479/0x27c0 ctnetlink_create_expect+0x22b/0x3b0 ctnetlink_new_expect+0x4bd/0x5c0 nfnetlink_rcv_msg+0x67a/0x950 netlink_rcv_skb+0x120/0x350 Allowing to read kernel memory bytes off the expectation boundary. CTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace via netlink dump.

CVSS: 7.3 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
Weakness (CWE): CWE-125
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 bd0779370588386e4a67ba5d0b176cfded8e6a53 before e135f8e8212cbed12a03ab8dec77fa1247139897; from bd0779370588386e4a67ba5d0b176cfded8e6a53 before 2ea0f35f235f70c133ad61fe05ba013753b978c6; from bd0779370588386e4a67ba5d0b176cfded8e6a53 before 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd; from bd0779370588386e4a67ba5d0b176cfded8e6a53 before 187b6ec5229ea93cb04c4f6d3b52efc80f513d0d; from bd0779370588386e4a67ba5d0b176cfded8e6a53 before 21a04c31db4057deec85fcd6cc63d720b38819c3; from bd0779370588386e4a67ba5d0b176cfded8e6a53 before 917b61fa2042f11e2af4c428e43f08199586633a	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 3.12 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/e135f8e8212cbed12a03ab8dec77fa1247139897	patch
https://git.kernel.org/stable/c/2ea0f35f235f70c133ad61fe05ba013753b978c6	patch
https://git.kernel.org/stable/c/0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cd	patch
https://git.kernel.org/stable/c/187b6ec5229ea93cb04c4f6d3b52efc80f513d0d	patch
https://git.kernel.org/stable/c/21a04c31db4057deec85fcd6cc63d720b38819c3	patch
https://git.kernel.org/stable/c/917b61fa2042f11e2af4c428e43f08199586633a	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.