CVE-2026-64564 is a serious security vulnerability in the Linux kernel, the core software that supports many business servers, cloud workloads, network appliances, and container platforms. Your organization may be exposed if it operates Linux systems with the Stream Control Transmission Protocol enabled, particularly systems supporting telecommunications, financial services, industrial, or other specialized network applications.
The vulnerability can allow an attacker to disrupt a system and may create a path to complete control of an affected host. Because Linux is embedded across modern infrastructure, the issue deserves attention even when your organization does not directly manage Linux applications.
This post explains why CVE-2026-64564 matters to your business, how to determine whether you are affected, what actions to take, and what security professionals should verify during technical assessment.
CVE-2026-64564 affects the Linux kernel’s implementation of Stream Control Transmission Protocol, or SCTP. The flaw involves improper handling of address-removal requests and can cause the kernel to reuse memory after it has been released. In plain language, an attacker may cause the operating system to rely on an invalid internal object.
The vulnerability was publicly disclosed and added to the National Vulnerability Database on August 4, 2026. Kernel.org is the assigning authority. The National Vulnerability Database has not yet published its own score, while the originating Linux security information assigns a CVSS 3.1 score of 9.8, rated Critical. Its vector indicates network reachability, low attack complexity, no required privileges, no user interaction, and potentially high impact to confidentiality, integrity, and availability.
The issue was tracked upstream through a Linux kernel fix and later documented in vendor advisories. Red Hat classifies its affected products separately because SCTP is disabled by default in Red Hat Enterprise Linux 8, 9, and 10.
You face two primary risks: service disruption and unauthorized control of a Linux system. An attacker may be able to send specially constructed network traffic that causes a kernel failure, potentially taking an application, server, or service offline. If exploitation reaches code execution, the attacker could operate with the highest operating-system privileges.
Operational consequences may include interrupted customer services, unavailable internal systems, failed transactions, disrupted communications, and emergency recovery costs. If the affected host supports payment processing, healthcare operations, telecommunications, logistics, or industrial functions, even a short outage may create contractual and financial consequences.
Data exposure is also possible if an attacker gains control of the host. That could include credentials, customer records, intellectual property, configuration files, encryption material, or access tokens used to reach other systems.
You may also face regulatory and contractual obligations. A compromise can trigger investigation, notification, evidence-preservation, and reporting requirements under applicable United States or Canadian rules and industry agreements. Even when no breach occurs, failing to address a critical vulnerability can complicate cyber insurance reviews, customer assessments, and audit discussions.
Regional bank: A Linux server supporting specialized financial communications runs SCTP and is reachable from a partner network. An attacker exploits the flaw to crash the host during a processing window, delaying transactions and forcing the bank to activate contingency procedures.
Healthcare provider: A hospital uses Linux-based systems for communications between clinical platforms. A compromised server gives an attacker privileged access to service credentials, increasing the risk of lateral movement into systems containing protected health information.
Telecommunications provider: A carrier operates Linux infrastructure that depends on SCTP for signaling or control traffic. Exploitation could interrupt a critical network function, degrade service availability, and create customer-facing outages across a region.
Small technology company: A software company runs containerized Linux workloads in a cloud environment. A low-privileged process or compromised container reaches the vulnerable kernel, potentially allowing the attacker to escape isolation and access neighboring workloads or host-level resources.
sctp kernel module is loaded, available to applications, or required by a business service.Do not let an unverified Linux exposure become an operational incident. IntegSec can help you identify vulnerable systems, validate whether SCTP is genuinely required, test your external and internal attack surface, and prioritize remediation across your environment. Contact IntegSec for a focused penetration test and a practical plan to reduce cybersecurity risk.
CVE-2026-64564 is a use-after-free vulnerability in the Linux kernel SCTP implementation, specifically Dynamic Address Reconfiguration processing for ASCONF chunks. The root cause is an identity mismatch: validation checks the packet source address, while the cached transport may correspond to an address parameter selected during ASCONF lookup.
A crafted ASCONF can place a DEL-IP operation for the cached transport before a wildcard DEL-IP operation. The first operation releases the transport, while the second reuses the dangling pointer. Kernel functions including sctp_assoc_set_primary() and sctp_assoc_del_nonprimary_peers() can then dereference freed memory and corrupt SCTP association state.
The upstream CVE record lists a network, low-complexity, unauthenticated attack with no user interaction and a CVSS 3.1 vector of AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Red Hat’s product-specific assessment is local, requires low privileges, and scores the issue 7.8.
The weakness is CWE-825, Expired Pointer Dereference. The vulnerable code path dates back to Linux kernel 2.6.25.
Version and module enumeration:
Scanner signatures: Vulnerability scanners may identify CVE-2026-64564 through Linux kernel package comparison, distribution errata, or detection of the loaded SCTP module. Validate scanner results against the operating system vendor’s advisory because vendors may backport the fix without changing the upstream-looking version.
Log indicators: Review kernel logs for SCTP warnings, association failures, unexpected transport removal, invalid memory access, kernel oops messages, general protection faults, or unexpected reboots.
Behavioral and network indicators: Look for unusual inbound SCTP traffic, unexpected ASCONF or DEL-IP activity, repeated SCTP association resets, crashes in hosts with SCTP enabled, and traffic from sources that do not normally participate in SCTP communications. Capture and analyze suspected traffic in a controlled environment. Do not send exploit payloads to production systems.
sctp module loaded or available, prioritize Internet-facing and partner-facing systems, and apply the official distribution kernel update. Reboot when required so the corrected kernel is running. Confirm the running kernel after reboot. If patching cannot occur immediately and the service does not require SCTP, prevent the module from loading:Regenerate the initramfs according to the distribution, then reboot. Red Hat documents this approach for systems where SCTP is not required.