How severe is CVE-2026-45952?

CVE-2026-45952 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-45952 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-2026-45952?

CVE-2026-45952 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-45952?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-45952 have an EU (EUVD) identifier?

Yes. CVE-2026-45952 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32236.

When was CVE-2026-45952 published?

CVE-2026-45952 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2026-45952

CVE-2026-45952 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-32236
Affected product: Linux Linux Kernel
Published: 2026-05-27
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Add validation for MTU changes Increasing the MTU beyond the HDS threshold causes the hardware to fragment packets across multiple buffers. If a single-buffer XDP program is attached, the driver will drop all multi-frag frames. While we can't prevent a remote sender from sending non-TCP packets larger than the MTU, this will prevent users from inadvertently breaking new TCP streams. Traditionally, drivers supported XDP with MTU less than 4Kb (packet per page). Fbnic currently prevents attaching XDP when MTU is too high. But it does not prevent increasing MTU after XDP is attached.

Frequently asked questions

What is CVE-2026-45952?: In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Add validation for MTU changes Increasing the MTU beyond the HDS threshold causes the hardware to fragment packets across multiple buffers. If a single-buffer XDP program is attached, the driver will drop all multi-frag frames. While we can't prevent a remote sender from sending non-TCP packets larger than the MTU, this will prevent users from inadvertently breaking new TCP streams. Traditionally, drivers supported XDP with MTU less than 4Kb (packet per page). Fbnic currently prevents attaching XDP when MTU is too high. But it does not prevent increasing MTU after XDP is attached.
How severe is CVE-2026-45952?: CVE-2026-45952 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-45952 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-2026-45952?: CVE-2026-45952 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-45952?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-45952 have an EU (EUVD) identifier?: Yes. CVE-2026-45952 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32236.
When was CVE-2026-45952 published?: CVE-2026-45952 was published on 2026-05-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

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