CVE-2026-64582 Linux CVE debrief

Who should care

Linux kernel developers, Linux distribution maintainers, users of Linux-based systems, and security teams responsible for vulnerability management and patching should care about this vulnerability. They should review the official advisory and CVE record to understand the affected scope, severity, and vendor guidance. Additionally, they should assess their deployments, plan for vendor-supported updates or mitigations, and monitor for potential attacks. Affected product deployments in managed environments require confirmation, and an owner should be assigned for follow-up. Compensating controls for exposed systems should be reviewed while remediation is scheduled and verified. Relevant monitoring, detection, and logs for exposed assets should be checked, and exceptions should be tracked and retested. The item should only be closed after evidence of remediation is documented. Linux distributions and maintainers should prioritize patching and updating their kernels to prevent exploitation. Security teams should also review their asset inventory and implement necessary controls to mitigate the vulnerability. Furthermore, users of Linux-based systems should be aware of the potential risks and take necessary precautions to protect their systems. This may involve applying patches or updates as they become available, restricting access to affected systems, and monitoring for suspicious activity. By taking these steps, Linux kernel developers, Linux distribution maintainers, and users of Linux-based systems can help prevent exploitation of this vulnerability and protect their systems from potential attacks. The Linux community and kernel developers should also consider implementing additional security measures to prevent similar vulnerabilities in the future. Overall, a coordinated effort is necessary to address this vulnerability and ensure the security of Linux-based systems. Security teams and Linux kernel developers should work together to prioritize patching, implement compensating controls, and monitor for potential attacks to minimize the risk of exploitation. Linux distribution maintainers should also provide clear guidance on patching and updating kernels to help

Technical summary

The vulnerability is caused by a use-after-free issue in the `rxe_mmap` function. The `rxe_mmap_info` struct is removed from the `pending_mmaps` list and its `pending_lock` is released while its `kref` is still at 1. This can lead to a concurrent `DESTROY_CQ` ioctl call freeing the `rxe_mmap_info` struct, causing a use-after-free condition. The vulnerability can result in a kernel crash or a page-level use-after-free, potentially allowing an attacker to get a clean page-level UAF.

Defensive priority

High

Recommended defensive actions

• Apply the patch to fix the use-after-free vulnerability in the Linux kernel's RDMA/rxe subsystem.
• Restrict access to the affected system to prevent exploitation.
• Monitor the system for potential attacks.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The vulnerability is caused by a use-after-free issue in the `rxe_mmap` function. The `rxe_mmap_info` struct is removed from the `pending_mmaps` list and its `pending_lock` is released while its `kref` is still at 1. This can lead to a concurrent `DESTROY_CQ` ioctl call freeing the `rxe_mmap_info` struct, causing a use-after-free condition. The vulnerability can result in a kernel crash or a page-level use-after-free.

Official resources