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Medium severity5.5NVD Advisory· Published Mar 18, 2026· Updated May 21, 2026

CVE-2026-23247

CVE-2026-23247

Description

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

11

Linux/Kernel10 versions
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*+ 9 more
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*range: >4.11,<6.18.17
- cpe:2.3:o:linux:linux_kernel:4.10.14:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:4.11:-:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:4.11:rc6:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:4.11:rc7:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:4.11:rc8:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
- (no CPE)range: >= 4.12
- (no CPE)range: 4.11
osv-coords
pkg:linux/kernel
Range: >= 4.11.0, < 6.18.17

Patches

Vulnerability mechanics

References

3

News mentions

0

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