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PatchSiren cyber security CVE debrief

CVE-2026-53370 Linux CVE debrief

The Linux kernel was vulnerable to an issue in the perf/x86/intel component, specifically with ACR mask validation and configuration. The vulnerability has been resolved through several changes, including improving user space ACR mask validation, handling invalid ACR masks, and clearing stale hardware ACR masks. The changes address these issues by dropping invalid bits, continuing to iterate through all ACR events, and explicitly clearing stale hardware ACR masks. System administrators and security teams should review the official advisory and ensure that their systems are updated with the latest kernel patches.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-07-29
Advisory published
2026-07-19
Advisory updated
2026-07-29

Who should care

System administrators and security teams responsible for Linux kernel-based systems should be aware of this vulnerability and ensure that their systems are updated with the latest kernel patches. They should review the official advisory and ensure that their systems are configured according to the new ACR mask validation and configuration changes. Additionally, they should monitor system logs for any potential issues related to the perf/x86/intel component.

Technical summary

The vulnerability was caused by incomplete validation of user space ACR masks, early returns on invalid ACR masks, and not clearing stale hardware ACR masks. The changes address these issues by dropping invalid bits, continuing to iterate through all ACR events, and explicitly clearing stale hardware ACR masks. The vulnerability affects the Linux kernel, specifically the perf/x86/intel component. The ACR mask validation and configuration issues have been addressed through several changes. The changes ensure that the ACR mask is properly validated and configured, preventing potential issues.

Defensive priority

Medium

Recommended defensive actions

  • Apply the latest Linux kernel patches to ensure the vulnerability is resolved.
  • Review and update system configurations to align with the new ACR mask validation and configuration changes.
  • Monitor system logs for any potential issues related to the perf/x86/intel component.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-07-19T09:17:02.153Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the official advisory. The vulnerability affects the Linux kernel, specifically the perf/x86/intel component. The ACR mask validation and configuration issues have been addressed through several changes.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-53370 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-53370

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-53370 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-53370

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/5ad732a56be46aabf158c16aa0c095291727aaef

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/aab56b95bee3ff79176b13443cd9d7cfe9747df0

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/c05e01cef47d9b4969eae2dcf9467e2a555bcb4f

    416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.