External risk intelligence

Linux Kernel SCTP Out-of-Bounds Read Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.1)

CVE-2026-74287

The vulnerability exists in the Linux kernel's SCTP implementation during INIT or ASCONF processing. While these protocols operate at the network layer and are potentially reachable if SCTP is enabled on public-facing interfaces, the requirement for specific SCTP traffic makes widespread public exposure less common than standard web or gateway services.

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability involves a flaw in how the Linux kernel handles network communication parameters, specifically within the SCTP protocol. If unaddressed, it could allow for malicious inputs to cause out-of-bounds reads, potentially impacting system stability. The main concern is confirming relevance and exposure.

Addresses incorrect handling of network communication data.
Matters due to potential system stability impacts.
Confirm if your systems use this specific network protocol.

Attack Path

How an attacker could exploit the issue

An attacker could send specially crafted network traffic to a system running a vulnerable Linux kernel. If the system is configured to use the Stream Control Transmission Protocol (SCTP), the attacker could exploit a flaw in how the kernel processes certain network parameters. This could lead to unauthorized access to system memory, potentially impacting the system's integrity and availability.

Network access required.
Triggered by malformed SCTP parameters.
Risks unauthorized memory access.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could allow a malformed SCTP packet to cause out-of-bounds reads when parsing network configuration parameters within the Linux kernel. This could potentially impact system stability and availability when SCTP is in use and exposed to a malicious actor.

Linux kernel data integrity and availability.
Malformed network packets triggering reads.
System crashes or denial of service.

Operational Fix

Recommended remediation, mitigation, and detection steps

This vulnerability resides in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation, specifically within functions that process address confirmation parameters. Teams responsible for kernel maintenance, network services, or system hardening should investigate. The initial focus should be on identifying systems running the Linux kernel, confirming if SCTP is enabled and exposed externally, and understanding the criticality of those systems to prioritize remediation efforts.

Identify SCTP-enabled Linux systems.
Verify external reachability and business impact.
Plan remediation based on identified risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is the Linux kernel SCTP component affected by CVE-2026-74287?

The Linux kernel is the core of your operating system. SCTP (Stream Control Transmission Protocol) is a network transport protocol used for reliable data transmission, similar to TCP but with advanced features like multi-homing. This vulnerability affects the code that handles how the kernel validates configuration parameters sent by a remote peer during network setup.

How does CVE-2026-74287 cause an out-of-bounds read?

This is a memory handling flaw where the kernel fails to check if the data length specified in a network packet matches the actual size of the provided data buffer. Because the system trusts the malicious length declaration, it attempts to read past the allocated memory boundary. This can lead to unauthorized information access or system instability.

Do I need to be concerned about normal network traffic?

No. Ordinary, well-formed network traffic will not trigger this vulnerability. The issue is specifically tied to malformed SCTP packets sent during INIT or ASCONF processing paths. A system is only at risk if it is configured to use SCTP and receives these intentionally crafted, invalid messages designed to exploit the parsing logic.

Is my system at risk according to Halo Surface Signal?

Halo Surface Signal indicates this is a possible risk if your system runs an affected Linux kernel with SCTP enabled on public-facing interfaces. Because this protocol functions at the network layer, systems exposed to the internet are more reachable by external attackers compared to internal, isolated services where SCTP traffic is restricted.

What steps should I take if I run the Linux kernel?

First, determine if your environment uses the SCTP protocol, as many systems do not require it. If SCTP is in use, assess which systems are exposed to external network traffic. Coordinate with your infrastructure or kernel maintenance teams to review available updates from your Linux distribution, which will include the necessary code changes to correctly validate packet lengths.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.