CVE-2026-72055

Cross-namespace tunnel reconfiguration via incomplete capability check

Published Aug 15, 2026 · Updated Aug 15, 2026

Privilege escalation in the Linux kernel allows local users to reconfigure IPv6 VTI tunnels across network namespaces. vti6_changelink() checks CAP_NET_ADMIN only in dev_net(dev), then parses attributes and rewrites a tunnel owned by t->net without checking that namespace. Exploitation requires CAP_NET_ADMIN in the device namespace, obtainable inside an unprivileged user namespace, and can redirect, expose, inject, or interrupt tunneled traffic.

CVSS severity8.8
High
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in the Linux kernel allows local users to reconfigure IPv6 VTI tunnels across network namespaces. vti6_changelink() checks CAP_NET_ADMIN only in dev_net(dev), then parses attributes and rewrites a tunnel owned by t->net without checking that namespace. Exploitation requires CAP_NET_ADMIN in the device namespace, obtainable inside an unprivileged user namespace, and can redirect, expose, inject, or interrupt tunneled traffic.

The record

CVE
CVE-2026-72055
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-270, T1040
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=3.15
  2. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <0b2f9c908f930ec4be17d389723f9a202d6a883c
  3. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <b2b61c540571b3cc2f461e2a579ba2cc8c2a52cf
  4. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <c64b9ae7eb97e81d54b792910a3aeafd92566c79
  5. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <e2ac3b242c37dff323a964962e43854f4b1a2b79
  6. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <ef897249dc957089e6f7f11ceea699e093ad51bd
  7. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <f5254e7766b4ac02b66b2ccef896cd278503cb11
  8. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <f6e8b52a2cb3bbd72ddc2d44e474b907b9dcf5ba
  9. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <f97e93ebf2f9b8ef3b87f7a9371255e84d151587

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.15; version=61220ab349485d911083d0b7990ccd3db6c63297 <0b2f9c908f930ec4be17d389723f9a202d6a883c; version=61220ab349485d911083d0b7990ccd3db6c63297 <b2b61c540571b3cc2f461e2a579ba2cc8c2a52cf; version=61220ab349485d911083d0b7990ccd3db6c63297 <c64b9ae7eb97e81d54b792910a3aeafd92566c79; version=61220ab349485d911083d0b7990ccd3db6c63297 <e2ac3b242c37dff323a964962e43854f4b1a2b79; version=61220ab349485d911083d0b7990ccd3db6c63297 <ef897249dc957089e6f7f11ceea699e093ad51bd; version=61220ab349485d911083d0b7990ccd3db6c63297 <f5254e7766b4ac02b66b2ccef896cd278503cb11; version=61220ab349485d911083d0b7990ccd3db6c63297 <f6e8b52a2cb3bbd72ddc2d44e474b907b9dcf5ba; version=61220ab349485d911083d0b7990ccd3db6c63297 <f97e93ebf2f9b8ef3b87f7a9371255e84d151587

Published CVSS scores

7.8Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
8.8LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-270Privilege Context Switching Error
T1040Network Sniffing

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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