CVE-2026-31692

Unauthorized interface creation via missing peer capability check

Published Apr 30, 2026 · Updated Apr 30, 2026

Improper authorization in the Linux Kernel rtnetlink component allows local users to create paired devices in arbitrary network namespaces. rtnl_newlink() accepts a peer namespace for veth, vxcan, or netkit creation without calling netlink_ns_capable() to verify CAP_NET_ADMIN there. A local user namespace is required; the bypass permits unauthorized interface creation even in init_net, altering host network configuration.

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

What happened

Improper authorization in the Linux Kernel rtnetlink component allows local users to create paired devices in arbitrary network namespaces. rtnl_newlink() accepts a peer namespace for veth, vxcan, or netkit creation without calling netlink_ns_capable() to verify CAP_NET_ADMIN there. A local user namespace is required; the bypass permits unauthorized interface creation even in init_net, altering host network configuration.

The record

CVE
CVE-2026-31692
Published
Apr 30, 2026
Updated
Apr 30, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1548
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Apr 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 30, 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=2.6.33
  2. Affected versionversion=81adee47dfb608df3ad0b91d230fb3cef75f0060 <0975b64ffb34560042090a5986c3a02e6c80f36f
  3. Affected versionversion=81adee47dfb608df3ad0b91d230fb3cef75f0060 <7b735ef81286007794a227ce2539419479c02a5f
  4. Affected versionversion=81adee47dfb608df3ad0b91d230fb3cef75f0060 <d04cc16d3624218a5458b2b664ae431f1b3b334d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.33; version=81adee47dfb608df3ad0b91d230fb3cef75f0060 <0975b64ffb34560042090a5986c3a02e6c80f36f; version=81adee47dfb608df3ad0b91d230fb3cef75f0060 <7b735ef81286007794a227ce2539419479c02a5f; version=81adee47dfb608df3ad0b91d230fb3cef75f0060 <d04cc16d3624218a5458b2b664ae431f1b3b334d

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
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1548Abuse Elevation Control Mechanism

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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