Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_conncount: increase the connection clean up limit to 64
After the optimization to only perform one GC per jiffy, a new problem
was introduced. If more than 8 new connections are tracked per jiffy the
list won't be cleaned up fast enough possibly reaching the limit
wrongly.
In order to prevent this issue, only skip the GC if it was already
triggered during the same jiffy and the increment is lower than the
clean up limit. In addition, increase the clean up limit to 64
connections to avoid triggering GC too often and do more effective GCs.
This has been tested using a HTTP server and several
performance tools while having nft_connlimit/xt_connlimit or OVS limit
configured.
Output of slowhttptest + OVS limit at 52000 connections:
slow HTTP test status on 340th second:
initializing: 0
pending: 432
connected: 51998
error: 0
closed: 0
service available: YES
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.10.248 – < 5.10.252, 5.15.198 – < 5.15.202, 5.19 | 5.10.252 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 6.18.14-1 | — |
| Debian 13 | linux | 6.12.85-1 | — |
| Debian 12 | linux | 6.1.170-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1026.30 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1096.98 | — |
| Ubuntu 25.10 | linux +8 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-134.134 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1060.63 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1063.71 | USN-8606-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1062.69 | USN-8607-1 |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1063.69 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1058.64 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1045.48 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1060.61 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-134.134.1 | USN-8497-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1058.61 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1058.61.1 | USN-8492-2 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1029.30 | USN-8498-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1057.58 | USN-8492-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1060.64 | USN-8492-4 |
| Ubuntu 24.04 LTS | linux-riscv +26 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1032.33 | USN-8499-1 |
| Ubuntu 22.04 LTS | linux | 5.15.0-186.196 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1112.119 | USN-8575-2 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1060.63~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-azure +1 | 5.15.0-1117.126 | USN-8610-1, USN-8575-3 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1063.71~22.04.1 | USN-8606-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1062.69~22.04.1 | USN-8609-1 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1112.122 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1063.69~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1108.114 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1095.103 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-136.136~22.04.1 | USN-8619-1 |
| Ubuntu 22.04 LTS | linux-ibm | 5.15.0-1106.110 | USN-8575-2 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1060.61~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1107.113 | USN-8620-4 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1104.109 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-184.194 | USN-8575-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-134.134.1~22.04.1 | USN-8497-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1107.108 | USN-8575-2 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1058.61~22.04.1 | USN-8492-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1064.66 | USN-8576-2 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1053.53 | USN-8576-2 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1109.115 | USN-8575-3 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1057.58~22.04.1 | USN-8492-2 |
| Ubuntu 22.04 LTS | linux-raspi | 5.15.0-1106.109 | USN-8668-2 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-134.134~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1075.79 | USN-8575-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2049.50 | USN-8492-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1055.56 | USN-8492-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1104.106 | USN-8620-3 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1111.120 | USN-8575-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1055.56~22.04.1 | USN-8492-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1060.63+fips1 | USN-8492-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1062.69+fips1 | USN-8492-5 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-134.134+fips1 | USN-8492-5 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1063.69+fips1 | USN-8492-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1112.119+fips1 | USN-8575-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1117.126+fips1 | USN-8620-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-186.196+fips1 | USN-8575-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1112.122+fips1 | USN-8575-1 |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1112.119~20.04.1 | USN-8575-2 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1117.126~20.04.1 | USN-8620-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1117.126~20.04.2 | USN-8620-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1112.122~20.04.1 | USN-8668-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-186.196~20.04.1 | USN-8575-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 +1 | 5.15.0-1106.110~20.04.1 | USN-8597-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1107.113~20.04.1 | USN-8620-3 |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-184.194~20.04.1 | USN-8575-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1064.66~20.04.1 | USN-8576-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1109.115~20.04.1 | USN-8620-1 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | rv +74 | 6.12.0-211.63.1.el10_2 | ALSA-2026:76738 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.78.1.150700.17.43.2 | SUSE-SU-2026:3790-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1, SUSE-SU-2026:23897-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23887-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.38.1 | SUSE-SU-2026:23887-1, SUSE-SU-2026:23881-1 |
| SLE Micro 6.1 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23194-1, SUSE-SU-2026:23193-1 |
| SLE Micro 6.0 | kernel-rt +4 | 6.4.0-51.1 | SUSE-SU-2026:23244-1, SUSE-SU-2026:23241-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.78.1 | SUSE-SU-2026:3790-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_19 | 1-150700.1.5.1 | SUSE-SU-2026:3810-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_20 | 1-150700.15.3.2 | SUSE-SU-2026:3790-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt +2 | 6.4.0-150700.7.72.1 | SUSE-SU-2026:3810-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.22 | openSUSE-SU-2026:21910-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.38.1 | openSUSE-SU-2026:21910-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.77-99.140 +2 | 1:1.0-0.amzn2023 | ALAS2023-2026-1544, ALAS2023-2026-1543, ALAS2023-2026-1514 |
| Amazon Linux 2023 | perf +14 | 1:6.1.166-197.305.amzn2023 | ALAS2023-2026-1544 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.77-99.140.amzn2023 | ALAS2023-2026-1543 |
| Amazon Linux 2023 | perf6.18 +14 | 1:6.18.15-14.217.amzn2023 | ALAS2023-2026-1514 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | rv +29 | 6.12.0-211.63.1.el10_2 | ELSA-2026-76738 |
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-204.92.4.2.el10uek | ELSA-2026-50372 |
Advisories 43
- WID-SEC-2026-1700 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8575-1 linux, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-realtime, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8575-2 linux-aws, linux-aws-5.15, linux-aws-fips, linux-fips, linux-ibm, linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8620-1 linux-azure-5.15, linux-azure-fde-5.15, linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8620-3 linux-intel-iot-realtime, linux-intel-iotg-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8668-2 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8610-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8575-3 linux-azure, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8668-1 linux-gcp-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8576-1 linux-nvidia-tegra-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8576-2 linux-nvidia-tegra, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8620-4 linux-intel-iotg vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8620-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 9, 2026
- USN-8606-1 linux-azure, linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8607-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8597-1 linux-ibm-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8619-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8609-1 linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8499-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8497-1 linux-lowlatency, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8492-1 linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-ibm, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-2 linux-aws-6.8, linux-gcp-6.8, linux-gke, linux-gkeop, linux-ibm-6.8, linux-nvidia-lowlatency, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8498-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-3 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-5 linux-azure-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- USN-8492-4 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 6, 2026
- ALSA-2026:76738 Important: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ELSA-2026-76738 Important: kernel security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Oct 8, 2026
- SUSE-SU-2026:23902-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23887-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23897-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23881-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- openSUSE-SU-2026:21910-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 25, 2026
- SUSE-SU-2026:3810-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 31, 2026
- SUSE-SU-2026:23244-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23241-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:3790-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23193-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- SUSE-SU-2026:23194-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Aug 26, 2026
- ELSA-2026-50372 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- ALAS2023-2026-1543 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
- ALAS2023-2026-1544 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
- ALAS2023-2026-1514 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 16, 2026
References
- https://git.kernel.org/stable/c/a5c9e14e0e8923218ae881d5e78c990c07694966
- https://git.kernel.org/stable/c/13eede458fdf231f1bf96a398feea4ad1553f14c
- https://git.kernel.org/stable/c/fa85432d58c8e74b39333edbf8d28df2985dfc79
- https://git.kernel.org/stable/c/0792ad077d776c2dcf20f0484e2461ded1b77a24
- https://git.kernel.org/stable/c/3d0994ed0aa1fc0a2c5e620b765e8defdd021bff
- https://git.kernel.org/stable/c/6e5fa7add3e76da068a478d905be64be8fa4e80a
- https://git.kernel.org/stable/c/0af0812baf2d363176c9b76fc07e33f13aede8db
- https://git.kernel.org/stable/c/21d033e472735ecec677f1ae46d6740b5e47a4f3