How severe is CVE-2026-23437?

CVE-2026-23437 has a CVSS 3.x base score of 7.8, 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 high, and availability high.

Is CVE-2026-23437 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-2026-23437?

CVE-2026-23437 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-23437?

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-2026-23437 have an EU (EUVD) identifier?

Yes. CVE-2026-23437 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18678.

When was CVE-2026-23437 published?

CVE-2026-23437 was published on 2026-04-03 and last updated on 2026-06-17.

CVE-2026-23437

CVE-2026-23437 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-18678
Affected product: Linux Linux Kernel
Published: 2026-04-03
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: net: shaper: protect late read accesses to the hierarchy We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.

Frequently asked questions

What is CVE-2026-23437?: In the Linux kernel, the following vulnerability has been resolved: net: shaper: protect late read accesses to the hierarchy We look up a netdev during prep of Netlink ops (pre- callbacks) and take a ref to it. Then later in the body of the callback we take its lock or RCU which are the actual protections. This is not proper, a conversion from a ref to a locked netdev must include a liveness check (a check if the netdev hasn't been unregistered already). Fix the read cases (those under RCU). Writes needs a separate change to protect from creating the hierarchy after flush has already run.
How severe is CVE-2026-23437?: CVE-2026-23437 has a CVSS 3.x base score of 7.8, 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 high, and availability high.
Is CVE-2026-23437 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-2026-23437?: CVE-2026-23437 primarily affects Linux Linux Kernel. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-23437?: 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-2026-23437 have an EU (EUVD) identifier?: Yes. CVE-2026-23437 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-18678.
When was CVE-2026-23437 published?: CVE-2026-23437 was published on 2026-04-03 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:*
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:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*

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