Riskcovery

CVE-2026-43025

netfilter: ctnetlink: ignore explicit helper on new expectations

State
Published
Severity
7.3 High
Published
May 1, 2026
Updated
Oct 19, 2026
Reserved
May 1, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.3 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HLinux

Weaknesses

Affected Products

ProductVersions
LinuxLinux
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before e135f8e8212cbed12a03ab8dec77fa1247139897Affected
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before 2ea0f35f235f70c133ad61fe05ba013753b978c6Affected
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before 0f6c33697ccfac6499d0b7a4dbdec5d3a3a566cdAffected
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before 187b6ec5229ea93cb04c4f6d3b52efc80f513d0dAffected
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before 21a04c31db4057deec85fcd6cc63d720b38819c3Affected
  • bd0779370588386e4a67ba5d0b176cfded8e6a53 to before 917b61fa2042f11e2af4c428e43f08199586633aAffected
LinuxLinux
  • 3.12Affected
  • before 3.12Not affected
  • 6.1.168 through 6.1.*Not affected
  • 6.6.134 through 6.6.*Not affected
  • 6.12.81 through 6.12.*Not affected
  • 6.18.22 through 6.18.*Not affected
  • 6.19.12 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.