# CVE-2026-53321: linux: In the Linux kernel, the following vulnerability has been resolved: io_uring/napi: cap busy_poll_to 10 msec Current... CVE-2026-53321 is fixed in 34 products on 1 platform, first by ALAS2023-2026-1866, released June 22, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-53321 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jun 22, 2026 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-64kb sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-64kb sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-azure sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-azure sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-default sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23237-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23237-1.md) | Aug 11, 2026 | | Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.37.1.160000.2.19 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-default-base sles 15.7 | 6.4.0-150700.53.78.1.150700.17.43.2 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-default-base sles 16.0 | 6.12.0-160000.37.1.160000.2.19 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-docs sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-docs sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-livepatch-6.18.33-63.124 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel-livepatch-SLE15-SP7-RT_Update_19 sles 15.7 | 1-150700.1.5.1 | [SUSE-SU-2026:3810-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3810-1.md) | Aug 26, 2026 | | Linux | kernel-livepatch-SLE15-SP7_Update_20 sles 15.7 | 1-150700.15.3.2 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-build sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-source sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-source sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-syms sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-syms sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.37.1 | [OPENSUSE-SU-2026:21555-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21555-1.md) | Aug 12, 2026 | | Linux | kernel-zfcpdump sles 15.7 | 6.4.0-150700.53.78.1 | [SUSE-SU-2026:3790-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-3790-1.md) | Aug 25, 2026 | | Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.37.1 | [SUSE-SU-2026:23231-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23231-1.md) | Aug 11, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-53321](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53321.md) | Jun 27, 2026 | | Linux | linux Debian 14 | 7.0.10-1 | [DEBIAN-CVE-2026-53321](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53321.md) | Jun 27, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.33-63.124.amzn2023 | [ALAS2023-2026-1866](https://patchblox.com/security/data/fix/linux/alas2023-2026-1866.md) | Jun 22, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.