CVE-2026-74736

Local kernel corruption via mismatched cls_bpf attachment

Published Aug 26, 2026 · Updated Aug 26, 2026

Origin validation error in cls_bpf in the Linux kernel allows local users to corrupt kernel memory through a mismatched device attachment. cls_bpf_prog_from_efd() accepts an offloaded SCHED_CLS program without confirming that its bound netdev matches the classifier's target, so deletion of the original device frees offload state still referenced by the second device. Exploitation requires namespace-local CAP_NET_ADMIN access and control of BPF loading, filter attachment, and device deletion; consequences include heap disclosure, arbitrary kernel writes, oops, hangs, or a panic.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Origin validation error in cls_bpf in the Linux kernel allows local users to corrupt kernel memory through a mismatched device attachment. cls_bpf_prog_from_efd() accepts an offloaded SCHED_CLS program without confirming that its bound netdev matches the classifier's target, so deletion of the original device frees offload state still referenced by the second device. Exploitation requires namespace-local CAP_NET_ADMIN access and control of BPF loading, filter attachment, and device deletion; consequences include heap disclosure, arbitrary kernel writes, oops, hangs, or a panic.

The record

CVE
CVE-2026-74736
Published
Aug 26, 2026
Updated
Aug 26, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-346, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 26, 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=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <120977e2c096deea4e866e4273be9220b957c29e
  2. Affected versionversion=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <5685bbbd3cbfbeb0de96a1d275a5ca073dfebb5e
  3. Affected versionversion=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <adb3e7c26a51a10d94a241c6de7a81a2863dcacf
  4. Affected versionversion=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <daf546ab5763ce6a18280cb4db060e836c515301
  5. Affected versionversion=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <ec5a552f4b2d841c6c021752450716e1a9676661
  6. Affected versionversion=6.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <120977e2c096deea4e866e4273be9220b957c29e; version=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <5685bbbd3cbfbeb0de96a1d275a5ca073dfebb5e; version=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <adb3e7c26a51a10d94a241c6de7a81a2863dcacf; version=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <daf546ab5763ce6a18280cb4db060e836c515301; version=2b3486bc2d237ec345b3942b7be5deabf8c8fed1 <ec5a552f4b2d841c6c021752450716e1a9676661; version=6.3

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/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
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

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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-346Origin Validation Error
T1499Endpoint Denial of Service

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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