CVE-2026-72053

Cross-namespace tunnel rewrite via incomplete capability check

Published Aug 15, 2026 · Updated Aug 15, 2026

Authorization bypass in the Linux kernel allows local users to rewrite IPIP tunnels across network namespaces through local rtnetlink requests. The ipip_changelink() path checks CAP_NET_ADMIN only against dev_net(dev), then passes attacker-controlled tunnel attributes to ip_tunnel_changelink() for a tunnel owned by t->net. A caller with CAP_NET_ADMIN in the device namespace but not the tunnel link namespace can redirect, inject, read, or interrupt tunneled IPv4 or MPLS traffic.

CVSS severity8.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authorization bypass in the Linux kernel allows local users to rewrite IPIP tunnels across network namespaces through local rtnetlink requests. The ipip_changelink() path checks CAP_NET_ADMIN only against dev_net(dev), then passes attacker-controlled tunnel attributes to ip_tunnel_changelink() for a tunnel owned by t->net. A caller with CAP_NET_ADMIN in the device namespace but not the tunnel link namespace can redirect, inject, read, or interrupt tunneled IPv4 or MPLS traffic.

The record

CVE
CVE-2026-72053
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1548
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 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=3.12
  2. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <26544021d5c49cc6ae8a968ccb5033e6363854a4
  3. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <68cadc3698c7de88966d306d12ec9c6217da228a
  4. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <8211a26324667980a463c069469a818e71207e02
  5. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <91571643e554ae89a91942380d5f5361fb7060a2
  6. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <983cc4aa7e6f633b34c3ee743771252d7afa9a90
  7. Affected versionversion=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <d49edcc65e0a37cc9b386a94415c5d6670ca8b71

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.12; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <26544021d5c49cc6ae8a968ccb5033e6363854a4; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <68cadc3698c7de88966d306d12ec9c6217da228a; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <8211a26324667980a463c069469a818e71207e02; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <91571643e554ae89a91942380d5f5361fb7060a2; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <983cc4aa7e6f633b34c3ee743771252d7afa9a90; version=6c742e714d8c282fd8f8b22d3e20b5141738c1ee <d49edcc65e0a37cc9b386a94415c5d6670ca8b71

Published CVSS scores

8.8Linux Kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
7.0SUSECVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.3SUSECVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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

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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