CVE-2026-89502

Kernel memory corruption via wrong-order page free

Published Sep 11, 2026 · Updated Sep 11, 2026

Improper page deallocation in the Linux kernel 6.8 ring buffer allows local users to corrupt kernel memory through trace-buffer teardown. rb_free_cpu_buffer() calls free_page() on cpu_buffer->free_page even when that allocation uses a subbuf_order greater than zero, so only an order-0 page is released. Triggering the defect requires a nonzero tracing sub-buffer order and sufficient local privilege to configure and tear down the tracing ring buffer.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper page deallocation in the Linux kernel 6.8 ring buffer allows local users to corrupt kernel memory through trace-buffer teardown. rb_free_cpu_buffer() calls free_page() on cpu_buffer->free_page even when that allocation uses a subbuf_order greater than zero, so only an order-0 page is released. Triggering the defect requires a nonzero tracing sub-buffer order and sufficient local privilege to configure and tear down the tracing ring buffer.

The record

CVE
CVE-2026-89502
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 <234b1a72e9706fe20c08c96f4374ec8e83b934cb
  3. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <77275ccea06eaf297e8e6ac3fc830cb72086379a
  4. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <81063bbb16c4fcf0136c9117d5e49d3621dd6a1e
  5. Affected versionversion=f9b94daa542a8d2532f0930f01cd9aec2d19621b <8c1ecdcdea738efe0494af908f12c0ae3a97fffa

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=6.8; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <234b1a72e9706fe20c08c96f4374ec8e83b934cb; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <77275ccea06eaf297e8e6ac3fc830cb72086379a; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <81063bbb16c4fcf0136c9117d5e49d3621dd6a1e; version=f9b94daa542a8d2532f0930f01cd9aec2d19621b <8c1ecdcdea738efe0494af908f12c0ae3a97fffa

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo