SEPTEMBER 18, 2026
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Case File

CVE-2026-89604

UNKNOWN · CVSS N/A EPSS 0.21%

Source: NVD + CISA KEV + EPSS · Published 2026-09-11 · Last synced 2026-09-18

CyberRota Analysis

AI-Generated

The vulnerability affects the Linux kernel's efivarfs mount point, where unprivileged users can exploit the statfs() handler to generate excessive calls to the costly QueryVariableInfo() runtime service. This can lead to performance degradation, particularly on x86 systems with SMM-backed variable stores, as it requires synchronization across all CPUs. System administrators and organizations using affected Linux distributions should prioritize applying the patch to mitigate potential denial-of-service conditions.

CVE
CVE-2026-89604
Severity
UNKNOWN
CVSS
N/A
EPSS
0.21%
Linux

Original NVD Description

In the Linux kernel, the following vulnerability has been resolved: efivarfs: Rate limit statfs() handler Ravi reports that statfs() may be called by unprivileged users on the efivarfs mount point, which may result in a flood of calls to the QueryVariableInfo() runtime service. These calls are disproportionately costly on x86 systems where the variable store is backed by SMM, as each SMM entry requires a rendez-vous of all the CPUs. So rate limit the calls to QueryVariableInfo() at twice per second, and return the most recently obtained value for calls that are elided.