CVE-2026-74628Network attack vector

Kernel crash via rearmed X.25 socket timer

Published Aug 22, 2026 · Updated Aug 25, 2026

Use-after-free in Linux kernel X.25 socket timers allows remote attackers to crash the kernel through concurrent X.25 traffic. The heartbeat callback rearms sk->sk_timer after __x25_destroy_socket() passes its cancellation point, so __sock_put() frees a still-queued socket that the next expiry dereferences. Exposure requires an X.25-capable kernel reachable by an unauthenticated peer and a race between socket teardown and a running timer callback.

CVSS severity9.8
Critical
EPSS probability0.50%
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 Linux kernel X.25 socket timers allows remote attackers to crash the kernel through concurrent X.25 traffic. The heartbeat callback rearms sk->sk_timer after __x25_destroy_socket() passes its cancellation point, so __sock_put() frees a still-queued socket that the next expiry dereferences. Exposure requires an X.25-capable kernel reachable by an unauthenticated peer and a race between socket teardown and a running timer callback.

The record

CVE
CVE-2026-74628
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-825, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1fc9f6d2c7c9fdb341bfe8ca449c990632299ea6
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2195424c3da2ef1829a63b807e3a900a90e57d85
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3c4919be5d910db4beebca420953858606fba7d8
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4bc522b33438fefc3272840ae5988771863a4f1f
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6b79659590f0f82a9b8efd2ffd55ec6399ebfc33
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e92c7e2b41d1528a830bc64c5e4e46dfa8133dda
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fdd9ac50b9b61ef2b2d52c5156aff788be91454d
  8. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1fc9f6d2c7c9fdb341bfe8ca449c990632299ea6; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2195424c3da2ef1829a63b807e3a900a90e57d85; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3c4919be5d910db4beebca420953858606fba7d8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4bc522b33438fefc3272840ae5988771863a4f1f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6b79659590f0f82a9b8efd2ffd55ec6399ebfc33; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e92c7e2b41d1528a830bc64c5e4e46dfa8133dda; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fdd9ac50b9b61ef2b2d52c5156aff788be91454d; version=2.6.12

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.5Red HatCVSS: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.

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-825Expired Pointer Dereference
T1499.004Application or System Exploitation

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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