CVE-2026-63797

Analyzed Analyzed - Analysis Complete

Use-After-Free in Linux Kernel RPMsg Char Device

Publication date: 2026-07-19

Last updated on: 2026-07-30

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: rpmsg: char: Fix use-after-free on probe error path rpmsg_chrdev_probe() stores the newly allocated eptdev in the default endpoint's priv pointer before calling rpmsg_chrdev_eptdev_add(). If rpmsg_chrdev_eptdev_add() then fails, its error path frees eptdev while the default endpoint may still dispatch callbacks with the stale priv pointer. Avoid publishing eptdev through the default endpoint until rpmsg_chrdev_eptdev_add() succeeds. Messages received before the priv pointer is published should be ignored by rpmsg_ept_cb(). Flow-control updates can hit rpmsg_ept_flow_cb() in the same window, so make both callbacks return success when priv is NULL.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-07-19

Last Modified

2026-07-30

Generated

2026-08-09

AI Q&A

2026-07-19

EPSS Evaluated

2026-08-07

NVD

CVE-2026-63797

EUVD

EUVD-2026-45463

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.2 (inc) to 6.6.144 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.95 (exc)
linux	linux_kernel	From 6.13 (inc) to 6.18.38 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.1.3 (exc)
linux	linux_kernel	From 5.18 (inc) to 6.1.178 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This vulnerability is a use-after-free issue in the Linux kernel's RPMSG subsystem. It occurs when the rpmsg_chrdev_probe function stores a newly allocated endpoint device in a default endpoint's private pointer before successfully adding it. If the addition fails, the endpoint device is freed while the default endpoint may still try to use the stale pointer, leading to potential memory corruption or crashes.

Detection Guidance

This vulnerability is specific to the Linux kernel's RPMSG subsystem and does not have a direct network-based detection method. It requires kernel-level inspection. Check if your kernel version includes the fix by running: uname -a. If your kernel version is below the patched version, the vulnerability may exist.

Impact Analysis

This vulnerability could cause system instability, crashes, or unexpected behavior in systems running vulnerable Linux kernel versions. It may lead to denial-of-service conditions or potential privilege escalation if exploited maliciously.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a use-after-free issue in the Linux kernel's rpmsg subsystem. It may indirectly impact compliance if exploited to cause system instability or crashes, potentially affecting data processing or availability.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the fix for this vulnerability. Monitor kernel security advisories and apply patches promptly. If immediate patching is not possible, consider disabling RPMSG-related modules if they are not essential to your system.

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