CVE-2026-74700

Kernel compromise via unlocked classifier destruction

Published Aug 22, 2026 · Updated Aug 25, 2026

Use-after-free in Linux kernel 5.1 and later traffic-control classifiers allows local users to crash the kernel or execute kernel code via a race. Concurrent u32 and flower creation at the same chain and priority lets the flower error path drop the last u32_tp reference, so tcf_proto_destroy calls tp->ops->destroy without rtnl_lock while another thread can reuse freed classifier memory. Reaching RTM_NEWTFILTER requires a local low-privileged process able to control two racing threads; successful exploitation can panic the host or gain kernel-level execution.

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 Linux kernel 5.1 and later traffic-control classifiers allows local users to crash the kernel or execute kernel code via a race. Concurrent u32 and flower creation at the same chain and priority lets the flower error path drop the last u32_tp reference, so tcf_proto_destroy calls tp->ops->destroy without rtnl_lock while another thread can reuse freed classifier memory. Reaching RTM_NEWTFILTER requires a local low-privileged process able to control two racing threads; successful exploitation can panic the host or gain kernel-level execution.

The record

CVE
CVE-2026-74700
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-763, T1068
Attack vector
local
Privileges
authenticated

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=12db03b65c2b90752e4c37666977fd4a1b5f5824 <34e77d8e3570f9df3952496ddb402833695662fd
  2. Affected versionversion=12db03b65c2b90752e4c37666977fd4a1b5f5824 <a347304b2ca1a5377d5bd2d8a72e4b4f12afe648
  3. Affected versionversion=12db03b65c2b90752e4c37666977fd4a1b5f5824 <a81f9c44d87fb59d99fce72e29e02cab3a49a1c3
  4. Affected versionversion=12db03b65c2b90752e4c37666977fd4a1b5f5824 <b648c8a56531aeabd1c14f6b5cf1891e269b3756
  5. Affected versionversion=12db03b65c2b90752e4c37666977fd4a1b5f5824 <d6222af7274f08e7a1848131dc30319993d8f377
  6. Affected versionversion=5.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=12db03b65c2b90752e4c37666977fd4a1b5f5824 <34e77d8e3570f9df3952496ddb402833695662fd; version=12db03b65c2b90752e4c37666977fd4a1b5f5824 <a347304b2ca1a5377d5bd2d8a72e4b4f12afe648; version=12db03b65c2b90752e4c37666977fd4a1b5f5824 <a81f9c44d87fb59d99fce72e29e02cab3a49a1c3; version=12db03b65c2b90752e4c37666977fd4a1b5f5824 <b648c8a56531aeabd1c14f6b5cf1891e269b3756; version=12db03b65c2b90752e4c37666977fd4a1b5f5824 <d6222af7274f08e7a1848131dc30319993d8f377; version=5.1

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 kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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 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-763Release of Invalid Pointer or Reference
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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