CVE-2026-23247

tcp: secure_seq: add back ports to TS offset

State: Published
Severity: Not scored
Published: Mar 18, 2026
Updated: Oct 30, 2026
Reserved: Jan 13, 2026

Read the record on cve.org

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 025f532d8c5cfac77845e50daab7f478b360f2acAffected 28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before e873e8c16b2fb743a381a9e59c108e63512301ecAffected 28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 5da5662181ef8a251e3ba564903002c2e87de452Affected 28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before eae2f14ab2efccdb7480fae7d42c4b0116ef8805Affected 28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 46e5b0d7cf55821527adea471ffe52a5afbd9cafAffected 28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 165573e41f2f66ef98940cf65f838b2cb575d9d1Affected 443fac9f2618b93cbc5ab068dc594530236b3a23Affected 4.10.14 to before 4.11Affected
LinuxLinux	4.11Affected before 4.11Not affected 6.1.191 through 6.1.Not affected 6.6.160 through 6.6.Not affected 6.12.94 through 6.12.Not affected 6.18.17 through 6.18.Not affected 6.19.7 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 025f532d8c5cfac77845e50daab7f478b360f2acAffected
28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before e873e8c16b2fb743a381a9e59c108e63512301ecAffected
28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 5da5662181ef8a251e3ba564903002c2e87de452Affected
28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before eae2f14ab2efccdb7480fae7d42c4b0116ef8805Affected
28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 46e5b0d7cf55821527adea471ffe52a5afbd9cafAffected
28ee1b746f493b7c62347d714f58fbf4f70df4f0 to before 165573e41f2f66ef98940cf65f838b2cb575d9d1Affected
443fac9f2618b93cbc5ab068dc594530236b3a23Affected
4.10.14 to before 4.11Affected

LinuxLinux

4.11Affected
before 4.11Not affected
6.1.191 through 6.1.*Not affected
6.6.160 through 6.6.*Not affected
6.12.94 through 6.12.*Not affected
6.18.17 through 6.18.*Not affected
6.19.7 through 6.19.*Not affected
7.0 and laterNot affected

References

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