CVE-2023-54085

mptcp: fix NULL pointer dereference on fastopen early fallback

HIGH
7.5
CVSS Score
Published: December 24, 2025 at 01:06 PM UTC
Updated: October 15, 2026 at 10:17 PM UTC
1 product affected across 1 vendorLinux Kernel

Using Linux by Linux?

Get instant alerts when new vulnerabilities affect Linux - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: fix NULL pointer dereference on fastopen early fallback In case of early fallback to TCP, subflow_syn_recv_sock() deletes the subflow context before returning the newly allocated sock to the caller. The fastopen path does not cope with the above unconditionally dereferencing the subflow context.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

36b122baf6a8bd46b4a591f12f4ed17b222574086.2
Vendor states this is fixed in 95135835519b0ab931c39908b2c99e9fb3c9068b (fixed)
Vendor states this is fixed in c0ff6f6da66a7791a32c0234388b1bdc00244917 (fixed)
Vendor states this is fixed in 6.2 (unaffected)
Vendor states this is fixed in 6.2.12 (unaffected)
Vendor states this is fixed in 6.3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHLinux
Vector?

Quick Info

StatusDEFERRED

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card