CVE-2023-54085
kernel: Linux kernel: Denial of Service due to NULL pointer dereference in mptcp fastopen
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · December 24, 2025
Updated · October 29, 2026
Description
A flaw was found in the Linux kernel's Multipath TCP (mptcp) implementation. During an early fallback to TCP in the fastopen process, the system incorrectly deletes a subflow context before it is no longer needed. This can lead to a NULL pointer dereference, allowing a local attacker with low privileges to cause a Denial of Service (DoS) by crashing the system.
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
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference