CVE-2026-63971

Analyzed Analyzed - Analysis Complete

Race Condition in Linux Kernel SCTP Socket Handling

Publication date: 2026-07-19

Last updated on: 2026-10-02

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: sctp: fix race between sctp_wait_for_connect and peeloff sctp_wait_for_connect() drops and re-acquires the socket lock while waiting for the association to reach ESTABLISHED state. During this window, another thread can peeloff the association to a new socket via getsockopt(SCTP_SOCKOPT_PEELOFF), changing asoc->base.sk. After re-acquiring the old socket lock, sctp_wait_for_connect() returns success without noticing the migration — the caller then accesses the association under the wrong lock in sctp_datamsg_from_user(). Add the same sk != asoc->base.sk check that sctp_wait_for_sndbuf() already has, returning an error if the association was migrated while we slept.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-19

Last Modified

2026-10-02

Generated

2026-10-09

AI Q&A

2026-07-19

EPSS Evaluated

2026-10-08

NVD

CVE-2026-63971

EUVD

EUVD-2026-45744

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	From 5.16 (inc) to 6.1.176 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.35 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.143 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.93 (exc)
linux	linux_kernel	From 5.11 (inc) to 5.15.210 (exc)
linux	linux_kernel	7.1
linux	linux_kernel	From 6.19 (inc) to 7.0.12 (exc)
linux	linux_kernel	From 4.16 (inc) to 5.10.259 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a race condition between two operations: sctp_wait_for_connect and peeloff. sctp_wait_for_connect drops and re-acquires the socket lock while waiting for an association to reach the ESTABLISHED state. During this window, another thread can peel off the association to a new socket using getsockopt(SCTP_SOCKOPT_PEELOFF), changing the association's socket pointer. After re-acquiring the lock, sctp_wait_for_connect returns success without detecting this change, leading to incorrect access to the association under the wrong lock.

Detection Guidance

This vulnerability is specific to the Linux kernel's SCTP implementation and may not have direct detection commands. Monitor kernel logs for SCTP-related errors or crashes. Check for unexpected socket behavior or association migrations. Use tools like 'ss -tulnp' or 'netstat -tulnp' to inspect SCTP sockets.

Impact Analysis

This vulnerability could allow an attacker to manipulate the association migration process, potentially causing the kernel to access memory incorrectly. This might lead to system crashes, data corruption, or unauthorized access to sensitive information. Systems using SCTP (Stream Control Transmission Protocol) for network communication are primarily affected.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a race condition in the Linux kernel's SCTP implementation that could lead to incorrect socket state handling, but no evidence suggests it impacts data protection, privacy, or security controls required by these regulations.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for this vulnerability. If immediate patching is not possible, consider disabling SCTP if not required by your system. Monitor vendor advisories for kernel updates.

Hi! I’m here to help you understand CVE-2026-63971. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70