CVE-2026-23247

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.

CVSS 3.1

5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 5% of CVEs (scores of 2026-10-25)

Published

2026-03-18

Modified

2026-10-21

Record from

the NVD, synced 2026-10-22

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1
• https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf
• https://git.kernel.org/stable/c/5da5662181ef8a251e3ba564903002c2e87de452
• https://git.kernel.org/stable/c/e873e8c16b2fb743a381a9e59c108e63512301ec
• https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805

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