Infinite loop in Linux kernel - CVE-2026-90053
Published: September 19, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an infinite loop in the HTB packet classifier htb_classify() when processing packets with cyclic inner-class filter selections. A local user can configure cyclic HTB filters and send a packet to cause a denial of service.
Exploitation is reachable through an unprivileged user namespace that provides CAP_NET_ADMIN.
Affected software
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-kvm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-gke (Ubuntu package)
linux-aws-5.15 (Ubuntu package)
linux-lowlatency-hwe-5.15 (Ubuntu package)
linux-hwe-5.15 (Ubuntu package)
linux-fips (Ubuntu package)
linux-azure-5.15 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-ibm-5.15 (Ubuntu package)
linux-azure-fde-5.15 (Ubuntu package)
linux-intel-iotg (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gkeop (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-ibm (Ubuntu package)
linux-intel-iotg-5.15 (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-intel-iot-realtime (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux (Debian package)
How to mitigate CVE-2026-90053
linux-kvm (Ubuntu package) - update to 5.15.0-1111.116
linux-aws (Ubuntu package) - addressed in versions 5.15.0-1119.126, 7.0.0-1016.17
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1120.130, 7.0.0-1016.18
linux-azure (Ubuntu package) - update to 5.15.0-1125.134
linux-oracle (Ubuntu package) - addressed in versions 5.15.0-1116.122, 7.0.0-1015.16
linux-lowlatency (Ubuntu package) - update to 5.15.0-197.207
linux-gke (Ubuntu package) - update to 5.15.0-1115.121
linux-aws-5.15 (Ubuntu package) - update to 5.15.0-1119.126~20.04.1
linux-lowlatency-hwe-5.15 (Ubuntu package) - update to 5.15.0-197.207~20.04.1
linux-hwe-5.15 (Ubuntu package) - update to 5.15.0-202.212~20.04.1
linux-fips (Ubuntu package) - update to 5.15.0-202.212+fips1
linux-azure-5.15 (Ubuntu package) - update to 5.15.0-1125.134~20.04.1
linux-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-ibm-5.15 (Ubuntu package) - update to 5.15.0-1113.117~20.04.1
linux-azure-fde-5.15 (Ubuntu package) - update to 5.15.0-1124.133~20.04.1
linux-intel-iotg (Ubuntu package) - update to 5.15.0-1114.120
linux-realtime (Ubuntu package) - update to 5.15.0-1118.127
linux-gkeop (Ubuntu package) - update to 5.15.0-1102.110
linux-nvidia (Ubuntu package) - update to 5.15.0-1114.115
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-ibm (Ubuntu package) - addressed in versions 5.15.0-1113.117, 7.0.0-1017.17
linux-intel-iotg-5.15 (Ubuntu package) - update to 5.15.0-1114.120~20.04.1
linux-oracle-5.15 (Ubuntu package) - update to 5.15.0-1116.122~20.04.1
linux-gcp-5.15 (Ubuntu package) - update to 5.15.0-1120.130~20.04.1
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux-azure-fde (Ubuntu package) - update to 5.15.0-1124.133
linux-intel-iot-realtime (Ubuntu package) - update to 5.15.0-1111.115
linux-gcp-fips (Ubuntu package) - update to 5.15.0-1120.130+fips1
linux-aws-fips (Ubuntu package) - update to 5.15.0-1119.126+fips1
linux-azure-fips (Ubuntu package) - update to 5.15.0-1125.134+fips1
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17
linux (Debian package) - update to 6.12.111-1
External References
- https://git.kernel.org/stable/c/010d05df52cec053bdc67d82c5b61cc4996f3fde
- https://git.kernel.org/stable/c/729c4896ab829169f95915d65edd530325910b37
- https://git.kernel.org/stable/c/83bb11805b620c498d6417e0e409f26887981489
- https://git.kernel.org/stable/c/872317e84fd019ceffba125e62d31586e3336d41
- https://git.kernel.org/stable/c/8c9611f7ba3ea5594e41bac952363aa0966d3280
- https://git.kernel.org/stable/c/90a149ab1f8344b7f713e9a838f69fde9e8d2a51
- https://git.kernel.org/stable/c/e54be9aa503a0297b63aec530fbf760350effd45
Related Security Bulletins
- Infinite loop in Linux kernel sched
- Debian update for linux
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-oem-7.0
- Ubuntu update for linux, linux-aws, linux-gcp and more
- Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
- Ubuntu update for linux, linux-aws, linux-aws-5.15 and more