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Critical · 9.8 CVE-2026-74611 EUVD-2026-64548GHSA-g4xp-j3j4-vmrq

tls: rx: restore msg_iter before TLS 1.3 optimistic retry

Published Aug 22, 2026 · Updated Oct 30, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-6.12 Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-7.0 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-7.0 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.17 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fde-7.0 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-7.0 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-7.0 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-7.0 Package: linux-nvidia-bos Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oem-7.0 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-oracle-7.0 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-riscv-7.0 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

In the Linux kernel, the following vulnerability has been resolved:

tls: rx: restore msg_iter before TLS 1.3 optimistic retry

tls_decrypt_sg() advances msg->msg_iter when it maps user pages for
the optimistic TLS 1.3 zero-copy path. If the decrypted record turns
out not to be unpadded application data, tls_decrypt_sw() retries into
a kernel skb, but leaves the iterator advanced.

The subsequent copy from the skb then writes decrypted bytes again at
a later point in the caller iovecs while recvmsg() reports only the
post-retry length. A TLS peer can trigger this after the receiver
enables TLS_RX_EXPECT_NO_PAD.

Revert the iterator by the number of bytes consumed by the optimistic
mapping before retrying without zero-copy.

Add a selftest which sends a TLS 1.3 control record with
TLS_RX_EXPECT_NO_PAD enabled and verifies that recvmsg() does not
overwrite later iovecs beyond the returned length.

Affected products

VendorProductAffectedFixed
Linux Linux 6.0 6.1.191

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.

ReleasePackageFixed inAdvisory
Debian 14 linux 7.1.9-1 —
Debian 13 linux 6.12.115-2 —
Debian 12 linux No fix yet —
Debian 12 linux-6.12 6.12.115-2~deb12u1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield No fix yet —
Ubuntu 26.04 LTS linux 7.0.0-42.42 USN-8959-1
Ubuntu 26.04 LTS linux-aws 7.0.0-1016.17 USN-8959-1
Ubuntu 26.04 LTS linux-azure 7.0.0-1020.21 USN-9019-1
Ubuntu 26.04 LTS linux-azure-fde 7.0.0-1019.19 USN-9020-1
Ubuntu 26.04 LTS linux-gcp 7.0.0-1016.18 USN-8959-1
Ubuntu 26.04 LTS linux-gke 7.0.0-1010.11 USN-9020-1
Ubuntu 26.04 LTS linux-ibm +1 7.0.0-1017.17 USN-8960-1, USN-8959-1
Ubuntu 26.04 LTS linux-nvidia +1 No fix yet —
Ubuntu 26.04 LTS linux-oracle 7.0.0-1015.16 USN-8959-1
Ubuntu 26.04 LTS linux-raspi 7.0.0-1023.23 USN-9021-1
Ubuntu 26.04 LTS linux-realtime 7.0.0-43.43.1 USN-9020-1
Ubuntu 26.04 LTS linux-riscv 7.0.0-42.42.1 —
Ubuntu 24.04 LTS linux +45 No fix yet —
Ubuntu 24.04 LTS linux-aws-7.0 7.0.0-1017.18~24.04.1 USN-9020-1
Ubuntu 24.04 LTS linux-azure-fde-7.0 7.0.0-1019.19~24.04.1 USN-9020-1
Ubuntu 24.04 LTS linux-gcp-7.0 7.0.0-1017.19~24.04.1 USN-9020-1
Ubuntu 24.04 LTS linux-hwe-7.0 7.0.0-42.42~24.04.1 USN-8959-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1036.39 USN-8886-1
Ubuntu 24.04 LTS linux-oracle-7.0 7.0.0-1016.18~24.04.1 USN-9020-1
Ubuntu 24.04 LTS linux-riscv-7.0 7.0.0-42.42.1~24.04.1 —
Ubuntu 22.04 LTS linux-riscv +42 No fix yet —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
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-realtime +3 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips +3 No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +5 6.4.0-150700.53.87.3 SUSE-SU-2026:4935-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.87.3.150700.17.49.2 SUSE-SU-2026:4935-1
SLES 15 SP7 kernel-obs-build 6.4.0-150700.53.87.2 SUSE-SU-2026:4935-1
SLES 15 SP7 kernel-syms 6.4.0-150700.53.87.1 SUSE-SU-2026:4935-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.143.1 SUSE-SU-2026:4934-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.143.1.150600.12.66.3 SUSE-SU-2026:4934-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.40.1 SUSE-SU-2026:24446-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.40.1.160000.2.29 SUSE-SU-2026:24446-1
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.143.1.150600.12.66.3 SUSE-SU-2026:4934-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.143.1 SUSE-SU-2026:4934-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.40.1 SUSE-SU-2026:24446-1, SUSE-SU-2026:24437-1
SLES 16.0 kernel-default-base 6.12.0-160000.40.1.160000.2.29 SUSE-SU-2026:24446-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.40.1.160000.2.29 SUSE-SU-2026:24422-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.40.1 SUSE-SU-2026:24422-1, SUSE-SU-2026:24386-1
SLE Micro 6.1 kernel-default-base 6.4.0-159998.54.1.159998.21.39 SUSE-SU-2026:24379-1
SLE Micro 6.1 kernel-rt +4 6.4.0-159998.54.1 SUSE-SU-2026:24553-1, SUSE-SU-2026:24379-1
SLE Micro 6.0 kernel-default-base 6.4.0-159998.54.1.159998.21.40 SUSE-SU-2026:24371-1
SLE Micro 6.0 kernel-rt +4 6.4.0-159998.54.1 SUSE-SU-2026:24473-1, SUSE-SU-2026:24371-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.87.3 SUSE-SU-2026:4935-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_22 1-150700.1.3.1 SUSE-SU-2026:4940-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_23 1-150700.15.3.2 SUSE-SU-2026:4935-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.143.1 SUSE-SU-2026:4934-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_33 1-150600.13.5.1 SUSE-SU-2026:4934-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.81.1 SUSE-SU-2026:4940-1
ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.40.1.160000.2.29 openSUSE-SU-2026:22167-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.40.1 openSUSE-SU-2026:22167-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.18.48-107.148 +1 1:1.0-0.amzn2023 ALAS2023-2026-3402, ALAS2023-2026-3139
Amazon Linux 2023 perf6.12 +11 1:6.12.114-139.210.amzn2023 ALAS2023-2026-3402
Amazon Linux 2023 perf6.18 +12 1:6.18.48-107.148.amzn2023 ALAS2023-2026-3139

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel 6.6.161.1-1 —

Advisories 21

References