CVE-2026-74634

Local privilege escalation via ring-buffer use-after-free

Published Aug 22, 2026 · Updated Aug 25, 2026

Use-after-free in the Linux kernel ring buffer allows local users to gain kernel-level control through concurrent tracefs operations. ring_buffer_subbuf_order_set() frees buffer pages even while resize_disabled shows that a non-consuming iterator still holds page references. Low-privileged local tracefs access is required; concurrent reads and sub-buffer-size writes expose recycled kernel memory, corrupt the heap, crash the kernel, or enable control-flow hijacking.

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 ring buffer allows local users to gain kernel-level control through concurrent tracefs operations. ring_buffer_subbuf_order_set() frees buffer pages even while resize_disabled shows that a non-consuming iterator still holds page references. Low-privileged local tracefs access is required; concurrent reads and sub-buffer-size writes expose recycled kernel memory, corrupt the heap, crash the kernel, or enable control-flow hijacking.

The record

CVE
CVE-2026-74634
Published
Aug 22, 2026
Updated
Aug 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
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=6.8
  2. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <62978cf6347972c04130e4e841ba404504d92b32
  3. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <7568e9e717e7540bd05bcc007f5d76fcaff3cdff
  4. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <b45b91db41379ee5fb36c187d6d7c37b725cbe8e
  5. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <bf98d7b0d5a99991e47e66cee4eb1d3fa514be97

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.8; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <62978cf6347972c04130e4e841ba404504d92b32; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <7568e9e717e7540bd05bcc007f5d76fcaff3cdff; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <b45b91db41379ee5fb36c187d6d7c37b725cbe8e; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <bf98d7b0d5a99991e47e66cee4eb1d3fa514be97

Published CVSS scores

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

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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