Improper input validation in Linux kernel - CVE-2026-90050
Published: September 19, 2026
Vulnerability identifier: #VU151430
CSH Severity: Low
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-90050
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper input validation in the fq qdisc change path when processing TCA_FQ_QUANTUM and TCA_FQ_INITIAL_QUANTUM configuration attributes. A local user can configure a qdisc with a small quantum value to cause a denial of service.
Exploitation requires CAP_NET_ADMIN in the relevant network namespace and CONFIG_NET_SCH_FQ to be enabled.
Affected software
Linux kernel
How to mitigate CVE-2026-90050
Install security update from vendor's repository.