How severe is CVE-2026-43025?

CVE-2026-43025 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability high.

Is CVE-2026-43025 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43025?

CVE-2026-43025 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-43025?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-43025 have an EU (EUVD) identifier?

Yes. CVE-2026-43025 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26624.

When was CVE-2026-43025 published?

CVE-2026-43025 was published on 2026-05-01 and last updated on 2026-06-17.

CVE-2026-43025

CVE-2026-43025 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: High (CVSS 3.x base score 7.3)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26624
Weakness: CWE-125
Affected product: Linux Linux Kernel
Published: 2026-05-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-43025?: 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.
How severe is CVE-2026-43025?: CVE-2026-43025 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability high.
Is CVE-2026-43025 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43025?: CVE-2026-43025 primarily affects Linux Linux Kernel. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-43025?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-43025 have an EU (EUVD) identifier?: Yes. CVE-2026-43025 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26624.
When was CVE-2026-43025 published?: CVE-2026-43025 was published on 2026-05-01 and last updated on 2026-06-17.

References

Affected products (7)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*

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