CVE-2026-46319
kernel: net/sched: act_ct: Only release RCU read lock after ct_ft
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · June 9, 2026
Updated · October 30, 2026
Description
A flaw was found in the Linux kernel. A race condition in the act_ct module, specifically during the flow table lookup, can lead to a Use-After-Free (UAF) vulnerability. This occurs because a critical lock is released prematurely, allowing a memory object to be freed while still in use. An attacker could potentially exploit this to achieve privilege escalation.
Statement
This vulnerability is rated as Moderate impact because successful exploitation requires local execution privileges and winning a narrow race condition during network traffic control flow table initialization. Under standard configurations, defining traffic control actions requires elevated network administration privileges, which significantly confines the attack surface unless unprivileged user namespaces are available. While a use-after-free condition could potentially allow a local user to escalate privileges or destabilize the system, the tight timing window makes practical exploitation complex.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
To mitigate this issue, prevent module act_ct from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
CVSS / CWE
CVSS 3.1 · 7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-826 · Premature Release of Resource During Expected Lifetime