5.5
MEDIUM CVSS 3.1
CVE-2026-53321
io_uring/napi: cap busy_poll_to 10 msec
Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/napi: cap busy_poll_to 10 msec Currently there's no cap on the maximum amount of time that napi is allowed to poll if no events are found, which can lead to kernel complaints on a task being stuck as there's no conditional rescheduling done within that loop. Just cap it to 10 msec in total, that's already way above any kind of sane value that will reap any benefits, yet low enough that it's nowhere near being able to trigger preemption complaints.

INFO

Published Date :

June 26, 2026, 8:17 p.m.

Last Modified :

July 6, 2026, 8:12 p.m.

Remotely Exploit :

No

Source :

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

The following products are affected by CVE-2026-53321 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Apply kernel updates to cap napi polling time and prevent potential system hangs.
  • Update the Linux kernel to the latest version.
  • Ensure kernel configurations prevent extended napi polling.
  • Monitor system performance for any hangs.
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-2026-53321.

URL Resource
https://git.kernel.org/stable/c/39767f944a8c9e696566c37ad5b20131406c4b8d Patch
https://git.kernel.org/stable/c/cb3af525f8dfb8930f0c123e5755fa967a12d5c1 Patch
https://git.kernel.org/stable/c/df8599ee18c0e5fe343ffe0b4c379636b8bb839a Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53321 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-2026-53321 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).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-53321 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-53321 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.

  • Initial Analysis by [email protected]

    Jul. 06, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Added CWE NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.9 up to (excluding) 6.18.33
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/39767f944a8c9e696566c37ad5b20131406c4b8d Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/cb3af525f8dfb8930f0c123e5755fa967a12d5c1 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/df8599ee18c0e5fe343ffe0b4c379636b8bb839a Types: Patch
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jun. 26, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5', 'lessThan': '39767f944a8c9e696566c37ad5b20131406c4b8d', 'versionType': 'git'}, {'status': 'affected', 'version': '8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5', 'lessThan': 'cb3af525f8dfb8930f0c123e5755fa967a12d5c1', 'versionType': 'git'}, {'status': 'affected', 'version': '8d0c12a80cdeb80d5e0510e96d38fe551ed8e9b5', 'lessThan': 'df8599ee18c0e5fe343ffe0b4c379636b8bb839a', 'versionType': 'git'}], 'programFiles': ['io_uring/napi.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.9'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.9', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.33', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['io_uring/napi.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: io_uring/napi: cap busy_poll_to 10 msec Currently there's no cap on the maximum amount of time that napi is allowed to poll if no events are found, which can lead to kernel complaints on a task being stuck as there's no conditional rescheduling done within that loop. Just cap it to 10 msec in total, that's already way above any kind of sane value that will reap any benefits, yet low enough that it's nowhere near being able to trigger preemption complaints.
    Added Reference https://git.kernel.org/stable/c/39767f944a8c9e696566c37ad5b20131406c4b8d
    Added Reference https://git.kernel.org/stable/c/cb3af525f8dfb8930f0c123e5755fa967a12d5c1
    Added Reference https://git.kernel.org/stable/c/df8599ee18c0e5fe343ffe0b4c379636b8bb839a
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.