Exposure of sensitive information to an unauthorized actor in Linux kernel - CVE-2026-23247
Published: March 20, 2026
Vulnerability identifier: #VU124203
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23247
CWE-ID: CWE-200
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper output neutralization in the TCP sequence number generation mechanism when handling SYN cookies. A remote attacker can send specially crafted TCP connection requests to disclose sensitive information.
The attacker can exploit the side-channel to infer TCP source ports, enabling off-path attacks that leak information about connection parameters.
How to mitigate CVE-2026-23247
Install security update from vendor's repository.