CVE-2026-68140

Received Received - Intake

Use-After-Free in Linux Kernel IUCV Subsystem

Publication date: 2026-08-10

Last updated on: 2026-08-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use-after-free of a severed iucv_path af_iucv queues not-yet-received message notifications on iucv->message_q, each holding a raw pointer to the connection's iucv_path. When the peer severs the connection, iucv_sever_path() frees that path with iucv_path_free() but leaves the notifications queued. A later recvmsg() drains message_q via iucv_process_message_q() and hands the stale path to message_receive() -- a use-after-free of the freed iucv_path. Drop the queued notifications when the path is severed; once the path is gone they can no longer be received. This also frees the notifications leaked when a socket is closed with messages still queued.

CVSS Scores

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Meta Information

Published

2026-08-10

Last Modified

2026-08-19

Generated

2026-08-30

AI Q&A

2026-08-10

EPSS Evaluated

2026-08-29

NVD

CVE-2026-68140

EUVD

EUVD-2026-55522

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability is a use-after-free flaw in the Linux kernel's IUCV (Inter-User Communication Vehicle) networking subsystem. It occurs when a connection's iucv_path is severed and freed, but message notifications queued for that path are not removed. Later, when processing these queued messages, the kernel tries to use the already-freed iucv_path, leading to memory corruption and potential system instability.

Detection Guidance

This vulnerability involves a use-after-free in the Linux kernel's IUCV (Inter-User Communication Vehicle) subsystem. Detection requires checking for kernel logs or crashes related to iucv_path use-after-free events. Monitor system logs for kernel oops or segmentation faults involving af_iucv or iucv_path. No specific commands are provided in the context to directly detect this issue.

Impact Analysis

This vulnerability could allow an attacker to crash the system or potentially execute arbitrary code with kernel privileges. It may lead to denial-of-service conditions, system instability, or unauthorized access if exploited. Systems using affected Linux kernel versions with IUCV networking enabled are at risk.

Compliance Impact

This vulnerability involves a use-after-free flaw in the Linux kernel's IUCV network subsystem, which could lead to memory corruption or crashes. While it does not directly impact data privacy or security controls, such kernel-level vulnerabilities may affect system stability and availability, indirectly influencing compliance with standards like GDPR or HIPAA that require secure and reliable processing of personal or health data.

Mitigation Strategies

Apply the Linux kernel patch that resolves this issue. Update your kernel to a version that includes the fix for CVE-2026-68140. If immediate patching is not possible, consider disabling the IUCV subsystem if it is not required by your system.

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