CVE-2026-45952

eth: fbnic: Add validation for MTU changes

MEDIUM
5.5
CVSS Score
Published: May 27, 2026 at 12:18 PM UTC
Updated: June 17, 2026 at 10:52 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.18 ≤ v < 6.18.146.18 ≤ v < 6.19.46.18 ≤ v < 7.06.19 ≤ v < 6.19.41b0a3950dbd4fa278dc33401a4faba2a23307a166.18
Vendor states this is fixed in 03399063aa0c67fd8bdfd69467ddb849bb3b97df (fixed)
Vendor states this is fixed in ccd8e87748ad083047d6c8544c5809b7f96cc8df (fixed)
Vendor states this is fixed in d7eaa006c0444a5d4671be7efe6dbb33ef8b515e (fixed)
Vendor states this is fixed in 6.18 (unaffected)
Vendor states this is fixed in 6.18.14 (unaffected)
Vendor states this is fixed in 6.19.4 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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