CVE-2026-43234

Local teardown hang via slave MTU notification

Published May 6, 2026 · Updated May 6, 2026

Reference-count leak in the Linux kernel team driver allows local users to hang network-device unregistration via netlink. During team_port_del, dev_set_mtu restores a departing slave's MTU and emits NETDEV_CHANGEMTU while NETDEV_UNREGISTER is in progress, causing inetdev_init to retain a net_device reference. Local users with network-administration capability in a namespace can leave unregister_netdevice waiting indefinitely, interrupting network-device teardown without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Reference-count leak in the Linux kernel team driver allows local users to hang network-device unregistration via netlink. During team_port_del, dev_set_mtu restores a departing slave's MTU and emits NETDEV_CHANGEMTU while NETDEV_UNREGISTER is in progress, causing inetdev_init to retain a net_device reference. Local users with network-administration capability in a namespace can leave unregister_netdevice waiting indefinitely, interrupting network-device teardown without reported data disclosure or modification.

The record

CVE
CVE-2026-43234
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=3.3
  2. Affected versionversion=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <5268892de70f0b29bde341db863b234aa9259c08
  3. Affected versionversion=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <bb4c698633c0e19717586a6524a33196cff01a32
  4. Affected versionversion=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <bce42728ac4887060a24a585c5122fbd24939db7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.3; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <5268892de70f0b29bde341db863b234aa9259c08; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <bb4c698633c0e19717586a6524a33196cff01a32; version=3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 <bce42728ac4887060a24a585c5122fbd24939db7

Published CVSS scores

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

T1499Endpoint Denial of Service

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo