Improper input validation in Linux kernel - CVE-2026-72398
Published: August 15, 2026
Vulnerability identifier: #VU143040
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72398
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to tamper with SCTP association handling and cause a denial of service.
The vulnerability exists due to improper input validation in SCTP COOKIE-ECHO processing paths when processing a cookie containing a reconstructed INIT chunk while cookie authentication is disabled. A remote attacker can send a specially crafted COOKIE-ECHO packet to tamper with SCTP association handling and cause a denial of service.
The issue only arises when cookie authentication is disabled.
Affected software
Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-72398
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14