CVE-2026-89984Public exploit

Kernel-address disclosure via incomplete LBR privilege filtering

Published Sep 16, 2026 · Updated Sep 16, 2026

Information disclosure in Linux allows local users to read kernel addresses through user-only Intel LBR branch stacks. The intel_pmu_lbr_filter() function validates a sampled branch's target privilege but fails to reject a kernel-space source address that violates the user-only filter. Reachability requires local perf branch sampling and affected Intel LBR hardware; the demonstrated consequence is address disclosure rather than kernel-memory access.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Linux allows local users to read kernel addresses through user-only Intel LBR branch stacks. The intel_pmu_lbr_filter() function validates a sampled branch's target privilege but fails to reject a kernel-space source address that violates the user-only filter. Reachability requires local perf branch sampling and affected Intel LBR hardware; the demonstrated consequence is address disclosure rather than kernel-memory access.

The record

CVE
CVE-2026-89984
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

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  1. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <3c492c8eba02698ca893a9a13388d2adf6dfb839
  2. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <68c4b780b266a435261a1e029bede5ee3c2735cc
  3. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <6ac26161db27f7fb9d9e89ae240dbe52795496cc
  4. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <b589147f54adc62e4172e4acf079ad5fb7b3687f
  5. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <be0628a101ac05b085aaa4f650d48bd3915e80fa
  6. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <ca19a175e89b7de604fab736436cbab74030b47a
  7. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <e2b0575900ff72aa82748af96e7bd564ade5157a
  8. Affected versionversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <f3705db4e6378cc1b91a38ce0fe2f879055e23ca
  9. Affected versionversion=5.9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=47125db27e47e9d44c878bf8925aa057824bb0d5 <3c492c8eba02698ca893a9a13388d2adf6dfb839; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <68c4b780b266a435261a1e029bede5ee3c2735cc; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <6ac26161db27f7fb9d9e89ae240dbe52795496cc; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <b589147f54adc62e4172e4acf079ad5fb7b3687f; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <be0628a101ac05b085aaa4f650d48bd3915e80fa; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <ca19a175e89b7de604fab736436cbab74030b47a; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <e2b0575900ff72aa82748af96e7bd564ade5157a; version=47125db27e47e9d44c878bf8925aa057824bb0d5 <f3705db4e6378cc1b91a38ce0fe2f879055e23ca; version=5.9

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

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

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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