CVE-2026-74707

Received Received - Intake

XSK Zero-Copy Metadata Validation Bypass in Linux Kernel

Publication date: 2026-08-22

Last updated on: 2026-08-25

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: xsk: validate metadata when processing requests The zero-copy path validates TX metadata while obtaining the descriptor context, then reads it again later when preparing the hardware request. User space can change the metadata between those operations and bypass the original validation. Validate the metadata in xsk_tx_metadata_request() and use the resulting flags snapshot for every feature check. Read request fields once so all zero-copy drivers process only values observed after successful validation.

CVSS Scores

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Meta Information

Published

2026-08-22

Last Modified

2026-08-25

Generated

2026-09-12

AI Q&A

2026-08-22

EPSS Evaluated

2026-09-10

NVD

CVE-2026-74707

EUVD

EUVD-2026-64394

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 in the Linux kernel involves improper validation of metadata in the zero-copy path. When processing requests, the kernel validates TX metadata initially but reads it again later when preparing hardware requests. An attacker in user space can modify the metadata between these steps, bypassing the original validation and potentially causing security issues.

Detection Guidance

This vulnerability affects the Linux kernel's XSK (AF_XDP) subsystem. Detection requires checking kernel versions and monitoring for unusual network activity. Use 'uname -r' to check your kernel version and compare it against patched versions. Monitor kernel logs for XSK-related errors with 'dmesg | grep xsk'. If you use AF_XDP applications, inspect their behavior for unexpected metadata changes.

Impact Analysis

This vulnerability could allow an attacker with access to the system to manipulate network packet metadata, potentially leading to unauthorized data access, denial of service, or privilege escalation. Systems using the Linux kernel's zero-copy network features are at risk.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it pertains to a low-level Linux kernel networking feature (XSK) and does not involve data exposure or privacy violations. Compliance impacts would depend on system-specific configurations and use cases rather than this vulnerability itself.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for this vulnerability. Monitor vendor advisories for patches and apply them promptly.

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