CVE-2026-68377

System crash via tunnel metadata use-after-free

Published Aug 10, 2026 · Updated Aug 10, 2026

Use-after-free in the Linux kernel act_tunnel_key module allows local users to crash the system through a tunnel_key action race. tunnel_key_release_params() synchronously drops the old metadata_dst while delaying only the params free, so tunnel_key_act() can clone a dead dst reference. Triggering the race requires local access, a network namespace with CAP_NET_ADMIN, and concurrent action replacement and packet transmission; the demonstrated result is kernel memory corruption and an oops or panic.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel act_tunnel_key module allows local users to crash the system through a tunnel_key action race. tunnel_key_release_params() synchronously drops the old metadata_dst while delaying only the params free, so tunnel_key_act() can clone a dead dst reference. Triggering the race requires local access, a network namespace with CAP_NET_ADMIN, and concurrent action replacement and packet transmission; the demonstrated result is kernel memory corruption and an oops or panic.

The record

CVE
CVE-2026-68377
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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=02239e797ac75f89a05622a27d04695f08c1ca89
  2. Affected versionversion=4.19.19 <4.20
  3. Affected versionversion=4.20.6 <4.21
  4. Affected versionversion=5.0
  5. Affected versionversion=9174c3df1cd181c14913138d50ccbe539bb08335 <2200a00ff247f70f5dcdb4e6f14b0d48ddac5467
  6. Affected versionversion=9174c3df1cd181c14913138d50ccbe539bb08335 <2791a501da508b704a617b4dba29db54a65bc9f7
  7. Affected versionversion=9174c3df1cd181c14913138d50ccbe539bb08335 <531dbb5bb98e52ad26be7e90f9f8bec707c5bd0e
  8. Affected versionversion=9174c3df1cd181c14913138d50ccbe539bb08335 <f1f5c8a3955f8fda3f84ed883ac8daa1847e724c
  9. Affected versionversion=9174c3df1cd181c14913138d50ccbe539bb08335 <fed1b1ddab41a0e7a462ac690a0c8af6ff793624
  10. Affected versionversion=ca9b7a65a2c97579fcdd509d454d48e3a5c49af8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=02239e797ac75f89a05622a27d04695f08c1ca89; version=4.19.19 <4.20; version=4.20.6 <4.21; version=5.0; version=9174c3df1cd181c14913138d50ccbe539bb08335 <2200a00ff247f70f5dcdb4e6f14b0d48ddac5467; version=9174c3df1cd181c14913138d50ccbe539bb08335 <2791a501da508b704a617b4dba29db54a65bc9f7; version=9174c3df1cd181c14913138d50ccbe539bb08335 <531dbb5bb98e52ad26be7e90f9f8bec707c5bd0e; version=9174c3df1cd181c14913138d50ccbe539bb08335 <f1f5c8a3955f8fda3f84ed883ac8daa1847e724c; version=9174c3df1cd181c14913138d50ccbe539bb08335 <fed1b1ddab41a0e7a462ac690a0c8af6ff793624; version=ca9b7a65a2c97579fcdd509d454d48e3a5c49af8

Published CVSS scores

7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/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 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

CWE-825Expired Pointer Dereference
T1068Exploitation for Privilege Escalation

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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