CVE-2026-23247
tcp: secure_seq: add back ports to TS offset
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.
INFO
Published Date :
March 18, 2026, 11:16 a.m.
Last Modified :
March 18, 2026, 11:16 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-23247
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the Linux kernel patch to secure sequence numbers.
- Ensure timestamp offset randomization includes TCP ports.
- Use a single siphash computation for ISN and TS offset.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-23247.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-23247 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-23247
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-23247 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-23247 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Mar. 18, 2026
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/165573e41f2f66ef98940cf65f838b2cb575d9d1 Added Reference https://git.kernel.org/stable/c/46e5b0d7cf55821527adea471ffe52a5afbd9caf Added Reference https://git.kernel.org/stable/c/eae2f14ab2efccdb7480fae7d42c4b0116ef8805