Vulnerability Database

374,078

Total vulnerabilities in the database

CVE-2026-53370 — linux / linux_kernel

In the Linux kernel, the following vulnerability has been resolved:

perf/x86/intel: Improve validation and configuration of ACR masks

Currently there are several issues on the user space ACR mask validation and configuration.

  • The validation for user space ACR mask (attr.config2) is incomplete, e.g., the ACR mask could include the index which belongs to another ACR events group, but it's not validated.
  • An early return on an invalid ACR mask caused all subsequent ACR groups to be skipped.
  • The stale hardware ACR mask (hw.config1) is not cleared before setting new hardware ACR mask.

The following changes address all of the above issues.

  • Figure out the event index group of an ACR group. Any bits in the user-space mask not present in the index group are now dropped.
  • Instead of an early return on invalid bits, drop only the invalid portions and continue iterating through all ACR events to ensure full configuration.
  • Explicitly clear the stale hardware ACR mask for each event prior to writing the new configuration.

Besides, a non-leader event member of ACR group could be disabled in theory. This could cause bit-shifting errors in the acr_mask of remaining group members. But since ACR sampling requires all events to be active, this should not be a big concern in real use case. Add a "FIXME" comment to notice this risk.

  • Published: Jul 19, 2026
  • Updated: Jul 30, 2026
  • CVE: CVE-2026-53370
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: Medium
  • Score: 5.5
  • AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

No CWE or OWASP classifications available.

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

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Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

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