CVE-2026-74559

Received Received - Intake

XSK descriptor overflow in Linux kernel

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: xsk: drain continuation descs after overflow in xsk_build_skb() Fix generic xmit path multi-buffer logic when packets are either too big (count of descriptors exceed MAX_SKB_FRAGS) or an invalid descriptor is included in fragmented packet. Introduce xdp_sock::drain_cont and act upon this flag - when it is set, keep on consuming descriptors from AF_XDP Tx ring and put them directly onto Cq. Previously these descriptors were silently lost and could never be reached again.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-05

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74559

EUVD

EUVD-2026-59624

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 a flaw in the xsk_build_skb() function where continuation descriptors are not properly drained after an overflow occurs. This can lead to descriptors being silently lost when packets are too large or contain invalid descriptors during fragmented transmission.

Detection Guidance

This vulnerability involves descriptor handling in AF_XDP Tx rings. To detect it, monitor for packet transmission failures or descriptor leaks in xsk_build_skb(). Check kernel logs for errors related to MAX_SKB_FRAGS or fragmented packets. Use commands like 'dmesg | grep xsk' or 'ethtool -S <interface>' to inspect ring buffer usage and errors.

Impact Analysis

The vulnerability may cause packet loss or corruption during network transmission, potentially disrupting network services or applications relying on AF_XDP sockets. Descriptors lost may not be recoverable, leading to incomplete data transmission.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR, HIPAA, or similar standards. The issue is specific to the Linux kernel's AF_XDP socket implementation, causing descriptor loss during packet transmission. No evidence suggests it affects data protection, privacy, or security controls required by these regulations.

Mitigation Strategies

Update the Linux kernel to the patched version that resolves the xsk_build_skb() vulnerability. Monitor network traffic for fragmented packets exceeding MAX_SKB_FRAGS or invalid descriptors in AF_XDP Tx rings.

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