CVE-2026-23247

tcp: secure_seq: add back ports to TS offset

CVE-2026-23247 is fixed in 58 products on 1 platform, first by DEBIAN-CVE-2026-23247, released March 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

Routine
CVSS
6.5
Moderate
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0017
6th percentile

In the Linux kernel, the following vulnerability has been resolved: tcp: secure_seq: add back ports to TS offset This reverts 28ee1b746f49 ("secure_seq: downgrade to per-host timestamp offsets") tcp_tw_recycle went away in 2017. Zhouyan Deng reported off-path TCP source port leakage via SYN cookie side-channel that can be fixed in multiple ways. One of them is to bring back TCP ports in TS offset randomization. As a bonus, we perform a single siphash() computation to provide both an ISN and a TS offset.

Where it's fixed

ProductFixed inFixReleased
Linux
bpftool6.18 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
bpftool6.18-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel-livepatch-6.18.20-20.229 · amzn 2023 1:1.0-0.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel-uek · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-devel · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-devel · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-deprecated · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-deprecated · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-desktop · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-desktop · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-extra · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-extra · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-extra-netfilter · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-extra-netfilter · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-usb · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-usb · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-wireless · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-debug-modules-wireless · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-devel · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-devel · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-doc · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-doc · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-deprecated · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-deprecated · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-desktop · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-desktop · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-extra · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-extra · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-extra-netfilter · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-extra-netfilter · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-usb · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-usb · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-wireless · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-modules-wireless · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-tools · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek-tools · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-devel · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-devel · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-core · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-core · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-deprecated · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-deprecated · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-desktop · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-desktop · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-extra · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-extra · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-extra-netfilter · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-extra-netfilter · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-usb · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-usb · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-wireless · ol 10 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel-uek64k-modules-wireless · ol 9 0:6.12.0-206.104.3.3.el9uek ELSA-2026-500248 Sep 4, 2026
kernel6.18 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-debuginfo-common-aarch64 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-debuginfo-common-x86_64 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-devel · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-headers · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-libbpf · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-libbpf-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-libbpf-devel · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-libbpf-static · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-modules-extra · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-modules-extra-common · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-tools · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-tools-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
kernel6.18-tools-devel · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
linux · Debian 13.5 (trixie) 6.12.94-1 DEBIAN-CVE-2026-23247 Mar 18, 2026
linux · Debian 14 6.19.8-1 DEBIAN-CVE-2026-23247 Mar 18, 2026
perf6.18 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
perf6.18-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
python3-perf6.18 · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026
python3-perf6.18-debuginfo · amzn 2023 1:6.18.20-20.229.amzn2023 ALAS2023-2026-1596 Apr 27, 2026

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