CVE-2026-63917

Cross-namespace kernel memory corruption via stale VTI entry

Published Jul 19, 2026 · Updated Jul 19, 2026

Use-after-free in IPv6 VTI handling in affected Linux Kernel releases allows local users to corrupt kernel memory across namespaces. vti6_changelink() and vti6_update() select the moved device's namespace instead of ip6_tnl.net, leaving a stale entry that cleanup_net() dereferences. CAP_NET_ADMIN inside an unprivileged user and network namespace is sufficient, and deleting the creation namespace can panic the host.

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

What happened

Use-after-free in IPv6 VTI handling in affected Linux Kernel releases allows local users to corrupt kernel memory across namespaces. vti6_changelink() and vti6_update() select the moved device's namespace instead of ip6_tnl.net, leaving a stale entry that cleanup_net() dereferences. CAP_NET_ADMIN inside an unprivileged user and network namespace is sufficient, and deleting the creation namespace can panic the host.

The record

CVE
CVE-2026-63917
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1611
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 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=3.15
  2. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <0cdce7618464f7fb06f461e8f4ad575cb1d570f4
  3. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <11b326fb0a374f4654f9be22d0f0f7abd9f7d3fe
  4. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <225b467e3b631f38be22e4b38062a1fed02fdd21
  5. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <d9c5eecdb3c740e65038651db7c686b10d76d1bc
  6. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <ee1778ba0f5cb53be771f97017d01eb356c797bf
  7. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <f1e89a943ee574d0f2f16246eb3f2d7330fdeb03
  8. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <f5c68875e25f331e497ddfbe81e2d8163a87f136
  9. Affected versionversion=61220ab349485d911083d0b7990ccd3db6c63297 <fc32be9ac2788524c6b24efd681cce7a6e731a92

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.15; version=61220ab349485d911083d0b7990ccd3db6c63297 <0cdce7618464f7fb06f461e8f4ad575cb1d570f4; version=61220ab349485d911083d0b7990ccd3db6c63297 <11b326fb0a374f4654f9be22d0f0f7abd9f7d3fe; version=61220ab349485d911083d0b7990ccd3db6c63297 <225b467e3b631f38be22e4b38062a1fed02fdd21; version=61220ab349485d911083d0b7990ccd3db6c63297 <d9c5eecdb3c740e65038651db7c686b10d76d1bc; version=61220ab349485d911083d0b7990ccd3db6c63297 <ee1778ba0f5cb53be771f97017d01eb356c797bf; version=61220ab349485d911083d0b7990ccd3db6c63297 <f1e89a943ee574d0f2f16246eb3f2d7330fdeb03; version=61220ab349485d911083d0b7990ccd3db6c63297 <f5c68875e25f331e497ddfbe81e2d8163a87f136; version=61220ab349485d911083d0b7990ccd3db6c63297 <fc32be9ac2788524c6b24efd681cce7a6e731a92

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

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1611Escape to Host

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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