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VulnerabilityPublished Updated

CVE-2026-89984: Linux kernel · perf/x86/intel: Fix kernel address leakages in LBR stack

Affects Linux kernelSource GCVE Database

0

Not known to be exploited.

Data as of 26 Oct 2026, 14:05 UTC

Severity
Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS
0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 16 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-5.5 – 7.0.0-38.38
23 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1003.3 – 7.0.0-1017.17
15 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1003.3 – 7.0.0-1016.16
9 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • 6.17.0-1002.2 – 7.0.0-1014.14
13 affected builds
Fixed in–
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • 7.0.0-1002.3 – 7.0.0-1008.9
6 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available that extends the privilege filtering in the intel_pmu_lbr_filter() function to validate both 'from' and 'to' addresses of LBR entries. Users should apply the updated Linux kernel versions that include this fix. Since this is a kernel vulnerability, upgrading to patched kernel versions is the recommended remediation. Patch status is not explicitly confirmed in the provided data; users should consult the vendor advisory for the latest remediation guidance.

Description

A vulnerability in the Linux kernel's perf subsystem on x86 Intel platforms allowed kernel addresses to leak into user-space branch stacks when using the Last Branch Record (LBR) feature. This occurred because the filtering mechanism did not fully validate the privilege level of sampled branch entries, allowing kernel branch records to be exposed even when user-only filtering was requested. The issue has been resolved by extending the filtering to validate both 'from' and 'to' addresses, preventing kernel addresses from appearing in user-only branch stacks.

References

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