CVE-2026-45952

TCP stream interruption via unchecked MTU change

Published May 27, 2026 · Updated May 27, 2026

Denial of service in the Linux kernel fbnic driver allows local users to interrupt new TCP streams by increasing an interface's MTU. The driver permits an MTU above the hardware HDS threshold after a single-buffer XDP program is attached, causing multi-buffer frames to be dropped. Exploitation requires permission to reconfigure an fbnic interface with XDP attached; the consequence is traffic loss rather than a system crash.

CVSS severity5.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux kernel fbnic driver allows local users to interrupt new TCP streams by increasing an interface's MTU. The driver permits an MTU above the hardware HDS threshold after a single-buffer XDP program is attached, causing multi-buffer frames to be dropped. Exploitation requires permission to reconfigure an fbnic interface with XDP attached; the consequence is traffic loss rather than a system crash.

The record

CVE
CVE-2026-45952
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <03399063aa0c67fd8bdfd69467ddb849bb3b97df
  2. Affected versionversion=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <ccd8e87748ad083047d6c8544c5809b7f96cc8df
  3. Affected versionversion=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <d7eaa006c0444a5d4671be7efe6dbb33ef8b515e
  4. Affected versionversion=6.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <03399063aa0c67fd8bdfd69467ddb849bb3b97df; version=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <ccd8e87748ad083047d6c8544c5809b7f96cc8df; version=1b0a3950dbd4fa278dc33401a4faba2a23307a16 <d7eaa006c0444a5d4671be7efe6dbb33ef8b515e; version=6.18

Published CVSS scores

7.5SUSECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7SUSECVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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