CVE-2026-64265

Analyzed Analyzed - Analysis Complete

Use-After-Free in Linux Kernel FUSE Subsystem

Publication date: 2026-07-25

Last updated on: 2026-08-12

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: fuse: clear intr_entry in fuse_resend and fuse_remove_pending_req When fuse_resend() moves a request from fpq->processing back to fiq->pending, it sets FR_PENDING and clears FR_SENT but does not remove the requests intr_entry from fiq->interrupts. If the request had FR_INTERRUPTED set from a prior signal, intr_entry remains dangling on fiq->interrupts. When the requesting task then receives a fatal signal, fuse_remove_pending_req() sees FR_PENDING=1, removes the request from fiq->pending and frees it via the refcount path, also without cleaning intr_entry. The stale intr_entry causes use-after-free when fuse_read_interrupt() iterates fiq->interrupts: - list_del_init(&req->intr_entry) -> UAF write on freed slab - req->in.h.unique -> UAF read, data leaked to userspace Remove intr_entry from fiq->interrupts in fuse_resend() for interrupted requests before they are placed back on fiq->pending. Add a WARN_ON if the intr_entry is not empty on request destruction.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-25

Last Modified

2026-08-12

Generated

2026-08-14

AI Q&A

2026-07-25

EPSS Evaluated

2026-08-13

NVD

CVE-2026-64265

EUVD

EUVD-2026-48977

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	From 6.13 (inc) to 6.18.39 (exc)
linux	linux_kernel	From 6.19 (inc) to 7.1.4 (exc)
linux	linux_kernel	From 6.9 (inc) to 6.12.96 (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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 is a use-after-free vulnerability in the Linux kernel's FUSE (Filesystem in Userspace) component. It occurs when a request is moved between processing and pending queues without properly clearing interrupt-related data. This leaves a dangling pointer that can be accessed after the memory is freed, leading to potential data leaks or crashes.

Detection Guidance

This vulnerability is specific to the Linux kernel's FUSE (Filesystem in Userspace) implementation. Detection requires checking kernel logs for use-after-free errors related to FUSE operations or examining kernel memory corruption patterns. No direct network detection commands are applicable. Review kernel logs with dmesg or journalctl for FUSE-related errors.

Impact Analysis

If exploited, this could allow an attacker to cause system crashes, leak sensitive data from kernel memory, or potentially escalate privileges. Users running systems with vulnerable kernel versions could experience instability or security breaches.

Compliance Impact

This vulnerability is a use-after-free issue in the Linux kernel's FUSE subsystem that could lead to data corruption or information disclosure. While it does not directly impact compliance with standards like GDPR or HIPAA, such vulnerabilities can undermine security controls required by these regulations by enabling unauthorized data access or system instability.

Mitigation Strategies

Apply the latest kernel update that includes the fix for this CVE. If immediate patching is not possible, consider disabling FUSE functionality temporarily or restricting access to FUSE-based filesystems until the patch is applied. Monitor kernel logs for signs of exploitation attempts.

Hi! I’m here to help you understand CVE-2026-64265. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70