Skip to content
VulniPulse
Sign in
Advisory severityMedium5.5Red Hat Linux

Medium [CVE-2026-53321] cap busy_poll_to 10 msec

This medium-severity Red Hat Linux advisory covers CVE-2026-53321 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat package: kernel-rt.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-53321 Source published Source updated

VulniPulse record published Record updated

CVE-2026-53321
Affected products & platforms
Red Hat LinuxLinux Kernel
Open source advisory

Summary

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. A flaw was found in the Linux kernel's io_uring subsystem, specifically in the Networked Asynchronous Packet Interface (NAPI) busy polling.

This vulnerability allows NAPI to poll indefinitely for events when none are present, which can cause a task to become stuck. This can lead to a Denial of Service (DoS) condition, making the system unresponsive.

The issue is addressed by implementing a 10-millisecond cap on the busy polling duration. Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Weakness: CWE-835. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9.

Red Hat does not currently list a fixing RHSA for this CVE.

Affected products named by the advisory: Red Hat package: kernel-rt.

Is CVE-2026-53321 exploited?

No exploitation is reported in the sources VulniPulse tracks: CVE-2026-53321 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.

How do I fix CVE-2026-53321?

The advisory VulniPulse tracks names no fixed release. Follow Red Hat's guidance for workarounds and updates.

Confirm against the vendor advisory before you patch.

Affected versions

No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.

Official advisory · medium-confidence parse· fetched 13 days ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.

Official advisory · medium-confidence parse· fetched 13 days ago·verify at source

Mitigation

The source record does not include mitigation steps. That does not mean no fix exists. Read the vendor advisory below for the authoritative guidance.

Official advisory · medium-confidence parse· fetched 13 days ago·verify at source

Get an email when Red Hat Linux Kernel publishes the next one.

See Red Hat Linux Kernel's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).

Alert me about Red Hat Linux Kernel

More Red Hat Linux advisories

All Red Hat Linux advisories

iPhone and Android apps · New on the App Store

Monitor future Red Hat Linux CVEs from your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.

Download on the App StoreGet CVE alerts on AndroidSee app features

Discussion(0)

No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.

Sign in to join the discussion.