CVE-2026-89604
efivarfs: Rate limit statfs() handler
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.
INFO
Published Date :
Sept. 11, 2026, 8:19 p.m.
Last Modified :
Sept. 14, 2026, 1:19 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the kernel patch for efivarfs statfs() handler.
- Ensure the kernel is updated to the resolved version.
- Monitor efivarfs mount point for excessive statfs() calls.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-89604.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-89604 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89604
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-89604 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89604 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 14, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89604.json">CVE-2026-89604</a> Added Reference https://git.kernel.org/stable/c/3cd611c9f1dbcc116c8af5112e3c1783c8cde2ae Added Reference https://git.kernel.org/stable/c/97d71ebee48cd1b29091762b3e5cca4f815dd84c -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89604.json">CVE-2026-89604</a> Added Reference https://git.kernel.org/stable/c/0dbc2e94b81df5a1264068b6ed3605c654b8afcb Added Reference https://git.kernel.org/stable/c/8953bdd1b9c0e748d5408d3d0b8e7aeee5c9cd41 Added Reference https://git.kernel.org/stable/c/92895a14329cc9533e2a74a265214f690ba3851a Added Reference https://git.kernel.org/stable/c/b2326338dc683e8c1067c0cbf7a47986c4190902