CVE-2026-74473

Received Received - Intake

Buffer Overflow in Linux Kernel VXLAN Module

Publication date: 2026-08-15

Last updated on: 2026-08-19

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: vxlan: use pskb_network_may_pull() in route_shortcircuit() route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data. However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length. Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-08-15

Last Modified

2026-08-19

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74473

EUVD

EUVD-2026-59666

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 function called route_shortcircuit() which incorrectly checks for available bytes in a network packet. It uses pskb_may_pull() starting from the MAC header, potentially leaving part of the IP header unchecked in fragmented packets. This could lead to reading beyond the intended buffer when accessing fields like ip_hdr(skb)->daddr.

Detection Guidance

This vulnerability affects the Linux kernel's VXLAN implementation and may lead to memory corruption or crashes. Detection requires checking kernel logs for VXLAN-related errors or crashes, particularly involving route_shortcircuit() or pskb_may_pull() failures. Monitor for kernel oops messages or network subsystem errors.

Impact Analysis

This flaw could allow an attacker to cause a denial-of-service by crashing the system or potentially execute arbitrary code with kernel privileges. It affects systems using VXLAN tunnels where route_shortcircuit() is called.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel networking issue that could lead to information disclosure or denial of service but does not inherently violate data protection or privacy regulations.

Mitigation Strategies

Apply the kernel patch that replaces pskb_may_pull() with pskb_network_may_pull() in the VXLAN route_shortcircuit() function. Update to a fixed kernel version if available. If immediate patching is not possible, disable VXLAN interfaces or restrict network access to reduce exposure.

Hi! I’m here to help you understand CVE-2026-74473. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70