CVE-2026-23247
Published: March 19, 2026Last modified: November 3, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.191-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://git.kernel.org/stable/c/025f532d8c5cfac77845e50daab7f478b360f2ac
- 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