In the Linux kernel, a critical vulnerability identified as CVE-2026-23450 has been reported, which allows for NULL pointer dereference and use-after-free conditions in the function smc_tcp_syn_recv_sock(). This issue arises in the TCP receive path when the SMC listen socket is closed concurrently, leading to potential crashes and service disruptions.
Severity for this vulnerability is rated as critical, with a CVSS score of 9.8. The implications are severe, as attackers may leverage this vulnerability to cause service interruptions or even data corruption. Organizations should prioritize patching immediately to mitigate risks associated with this vulnerability.
Currently, the vulnerability status is awaiting analysis, but given its potential impact, immediate attention is warranted. This vulnerability can be exploited through network access, and no user interaction is required, increasing its threat level.
Organizations should be aware of the urgency in addressing this vulnerability, as the risk to operations and data integrity is significant. Effective remediation includes applying the necessary patches as soon as they are available.
Vulnerability Details
The official description states that the vulnerability arises from issues in the smc_tcp_syn_recv_sock() function, which can be triggered during the TCP three-way handshake. The vulnerability can lead to a NULL pointer dereference or a use-after-free condition when accessing freed memory, particularly impacting the integrity and availability of network services.
The vulnerability is classified under the Common Weakness Enumeration (CWE) but specific CWE IDs were not provided. The publication date of this vulnerability was April 3, 2026, and it is critical that organizations take immediate steps to remediate.
Technical Analysis
The root cause of this vulnerability lies in improper handling of concurrent operations on the SMC listen socket. Specifically, when smc_close_active() sets sk_user_data to NULL, the original smc_sock object may be freed while still being accessed by other threads, leading to a crash or data corruption.
The attack vector is network-based, and the complexity of exploitation is low, as no privileges or user interaction are required. The potential impacts include high confidentiality, integrity, and availability losses, making this a significant threat to organizations.
Risk & Impact Analysis
Risk to organizations includes potential service outages and data integrity issues due to the exploitation of this vulnerability. The blast radius could be significant, affecting any services reliant on the Linux kernel for network functionality. Organizations are urged to assess their exposure and prioritize patching to mitigate this risk.
Given the critical CVSS score of 9.8 and the fact that this vulnerability is not currently listed in the Known Exploited Vulnerabilities (KEV) catalog, a proactive approach to remediation is essential. The urgency of addressing this vulnerability cannot be overstated.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Specific affected versions have not been detailed; however, it is important to note that all versions of the Linux kernel prior to the vendor patch are likely affected. Organizations should ensure they are running the latest versions to avoid exposure.
Mitigation & Remediation
To mitigate this vulnerability, organizations must apply the patches released by the Linux kernel maintainers as soon as they are available. In addition to patching, organizations should consider implementing configuration hardening, network controls, and continuous security testing to identify and remediate similar vulnerabilities.
For effective remediation, organizations can explore services like penetration testing to ensure that their systems are resilient against this and other vulnerabilities.
Detection Guidance
Organizations should monitor for log indicators that may signify attempts to exploit this vulnerability. Behavioral anomalies in network traffic, such as unexpected TCP SYN packets or unusual socket behavior, should also be investigated. Additionally, maintaining vigilance for system changes in the Linux kernel can assist in detecting any potential exploitation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-23450 is tied to the ongoing challenges of concurrency and memory management within network protocols. This vulnerability exemplifies the complexities faced by developers in ensuring memory safety while handling concurrent connections.
Security teams should learn from this incident by enhancing their security testing methodologies and ensuring robust review processes for code that handles concurrency. Adopting practices that prioritize memory safety can significantly reduce the attack surface.
For further insights on securing your applications, organizations can refer to our resources on penetration testing methodology and the importance of a comprehensive vulnerability management program to proactively address security risks.
For organizations leveraging cloud environments, understanding the nuances of cloud penetration testing can provide additional layers of security and assurance.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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