CVE Catalog

CVE-2026-43025

HighCVSS 7.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

3th percentile - higher than 3% of all known CVEs

Summary

A vulnerability in the Linux kernel netfilter ctnetlink module fails to validate the helper for new expectations, allowing an attacker to supply an arbitrary helper from userspace, leading to a slab-out-of-bounds read and potential kernel memory leak.

Risk Assessment

The organization risks exposure of sensitive kernel memory and potential system crashes due to malicious network packets triggering the out-of-bounds access.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit that ignores the user-suggested helper for new expectations).

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS