CVE-2026-23247
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 6.18.17
- Linux Kernel < 6.19.7
- Linux Kernel 4.10.14
- Linux Kernel 4.11
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-23247.md and follow it. Check whether this project is affected by CVE-2026-23247. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1
- https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf
- https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805
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