Description
In the Linux kernel, the following vulnerability has been resolved:
mptcp: close TOCTOU race while computing rcv_wnd
The MPTCP output path access locklessly the MPTCP-level ack_seq
in multiple times, using possibly different values for the data_ack
in the DSS option and to compute the announced rcv wnd for the same
packet.
Refactor the cote to avoid inconsistencies which may confuse the
peer. Also ensure that the MPTCP level rcv wnd is updated only when
the egress packet actually contains a DSS ack.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.11 | 5.15.210 |
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 | 7.0.13-1 | — |
| Debian 13 | linux | 6.12.94-1 | — |
| Debian 12 | linux | 6.1.176-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1032.37 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1101.103 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-31.31 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1012.12 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1014.14 | USN-8726-4 |
| Ubuntu 26.04 LTS | linux-gcp +1 | 7.0.0-1011.11 | USN-8726-4, USN-8726-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1006.7 | USN-8726-1 |
| Ubuntu 26.04 LTS | linux-ibm +2 | 7.0.0-1013.13 | USN-8727-1, USN-8726-3 |
| Ubuntu 26.04 LTS | linux-nvidia | 7.0.0-1018.18 | USN-8760-2 |
| Ubuntu 26.04 LTS | linux-nvidia-bos | 7.0.0-2018.18 | USN-8800-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1019.19 | USN-8726-2 |
| Ubuntu 26.04 LTS | linux-riscv +1 | 7.0.0-31.31.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux | 6.8.0-146.146 | USN-8903-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1066.69 | USN-8903-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1012.12~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-azure-7.0 | 7.0.0-1014.14~24.04.1 | USN-8728-2 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1068.75 | USN-8904-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1013.13~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gcp +1 | 6.8.0-1070.78 | USN-8905-2, USN-8904-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 +1 | 7.0.0-1011.11~24.04.1 | USN-8728-3, USN-8728-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1065.73 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1051.55 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-31.31~24.04.1 | USN-8726-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1066.67 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-146.146.1 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1064.67 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia-7.0 | 7.0.0-1018.18~24.04.1 | USN-8760-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1064.67.1 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1036.39 | USN-8886-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1063.66 | USN-8903-2 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +29 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-31.31.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1008.8 | — |
| Ubuntu 22.04 LTS | linux | 5.15.0-198.208 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1117.124 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1066.69~22.04.1 | USN-8903-1 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1123.132 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1122.131 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1068.75~22.04.1 | USN-8904-1 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1118.128 | USN-8877-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 +1 | 6.8.0-1070.78~22.04.1 | USN-8905-1, USN-8904-1 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1113.119 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1100.108 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-149.149~22.04.1 | USN-9066-1 |
| Ubuntu 22.04 LTS | linux-ibm | 5.15.0-1111.115 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1066.67~22.04.1 | USN-8906-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1112.118 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1109.114 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-195.205 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-146.146.1~22.04.1 | USN-8903-2 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1112.113 | USN-8875-2 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1064.67~22.04.1 | USN-8903-2 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1070.72 | USN-8963-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1059.59 | USN-8963-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1114.120 | USN-8875-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1067.71~22.04.1 | USN-9025-1 |
| Ubuntu 22.04 LTS | linux-raspi | 5.15.0-1113.116 | USN-9029-1 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-146.146~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1080.84 | USN-8875-1 |
Show 9 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 | 6.8.0-2056.58 | USN-9025-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1061.62 | USN-8903-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1109.111 | USN-8875-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1116.125 | USN-8875-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1061.62~22.04.1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1066.69+fips1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1069.77+fips1 | USN-8904-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-146.146+fips1 | USN-8903-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1070.78+fips1 | USN-8905-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1117.124+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1123.132+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-198.208+fips1 | USN-8875-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1118.128+fips1 | USN-8877-1 |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1117.124~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1123.132~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1122.131~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1118.128~20.04.1 | USN-8878-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 | 5.15.0-198.208~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 +1 | 5.15.0-1111.115~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1112.118~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-195.205~20.04.1 | USN-8875-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1070.72~20.04.1 | USN-8963-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1114.120~20.04.1 | USN-8879-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.36-69.134 +2 | 1:1.0-0.amzn2023 | ALAS2023-2026-1968, ALAS2023-2026-1925, ALAS2023-2026-1924 |
| Amazon Linux 2023 | perf +11 | 1:6.1.176-220.358.amzn2023 | ALAS2023-2026-1924 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.94-123.174.amzn2023 | ALAS2023-2026-1968 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.36-69.134.amzn2023 | ALAS2023-2026-1925 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-206.104.3.3.el10uek | ELSA-2026-500248 |
Advisories 32
- USN-8875-1 linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-azure, linux-azure-5.15, linux-azure-fde-5.15, linux-azure-fips, linux-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iot-realtime, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-oracle, linux-realtime, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8963-1 linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-1 linux, linux-aws, linux-aws-7.0, linux-gcp, linux-gke, linux-hwe-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8903-2 linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9029-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8903-1 linux, linux-aws, linux-aws-6.8, linux-aws-fips, linux-fips, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-1 linux-gcp-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8904-1 linux-azure, linux-azure-6.8, linux-azure-fde, linux-azure-fde-6.8, linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-4 linux-azure, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8879-1 linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8906-1 linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8905-1 linux-gcp-6.8, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8905-2 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8760-1 linux-nvidia-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-3 linux-oracle-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8728-2 linux-azure-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8800-1 linux-nvidia-bos vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8878-1 linux-gcp-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-2 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8877-1 linux-gcp, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8726-3 linux-ibm vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8875-2 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8727-1 linux-oem-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-8760-2 linux-nvidia vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- WID-SEC-2026-2403 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8886-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- ELSA-2026-500248 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Sep 4, 2026
- ALAS2023-2026-1924 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 12, 2026
- ALAS2023-2026-1968 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 12, 2026
- ALAS2023-2026-1925 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 29, 2026
References
- https://git.kernel.org/stable/c/301a33fd590c408a05c5df800e0cc1e6a8a2f8f8
- https://git.kernel.org/stable/c/68364963e5baf03f16b4420292291f75c8f66497
- https://git.kernel.org/stable/c/907ac6b1658e0277f979fcdfae2a753b495c1510
- https://git.kernel.org/stable/c/c4f4cf60797974873dbc8e100144682a6f2f861f
- https://git.kernel.org/stable/c/3b8cbba7c0ed31189c89f90be247b8973ffa79ef
- https://git.kernel.org/stable/c/8f4f0a157e8436a05bf8c3670b24dbc258911c43
- https://git.kernel.org/stable/c/8ab24fdebc369c0dfb90f82c1650b1e66662bb45