CVE-2026-74585
Received Received - Intake

Thunderbolt DROM Port Number Out-of-Bounds Access

Publication date: 2026-08-22

Last updated on: 2026-08-22

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Bound the DROM dual link port number before indexing sw->ports tb_drom_parse_entry_port() validates the device-supplied header->index against sw->config.max_port_number before indexing sw->ports[], but the sibling field entry->dual_link_port_nr -- a 6-bit value also read from the DROM -- indexes the same array with no such check. A malicious or malformed Thunderbolt device can set dual_link_port_nr beyond the allocated sw->ports[] (max_port_number + 1 entries), producing an out-of-bounds tb_port pointer that is stored and later dereferenced. Reject a port entry whose dual_link_port_nr exceeds max_port_number, the same bound already applied to header->index.

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Meta Information

Published
2026-08-22
Last Modified
2026-08-22
Generated
2026-08-22
AI Q&A
2026-08-22
EPSS Evaluated
N/A
NVD
CVE-2026-74585
EUVD
EUVD-2026-64522

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux_kernel linux_kernel *

Helpful Resources

Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a Linux kernel vulnerability in the Thunderbolt subsystem. A malicious or malformed Thunderbolt device can set a dual_link_port_nr value that exceeds the allowed port number limit. This causes an out-of-bounds access when indexing the sw->ports array, leading to a potential pointer corruption and later dereferencing of an invalid pointer.

Detection Guidance

This vulnerability is specific to the Linux kernel's Thunderbolt subsystem and requires kernel-level inspection. Detection involves checking kernel logs for Thunderbolt-related errors or examining the kernel version for affected code. Commands like dmesg | grep thunderbolt or uname -a may help identify vulnerable systems.

Impact Analysis

This vulnerability could allow an attacker with physical access to a system via a Thunderbolt device to cause a system crash, execute arbitrary code, or escalate privileges. It may also lead to data corruption or denial of service on affected systems.

Mitigation Strategies

Apply the latest Linux kernel updates provided by your distribution to patch this vulnerability. If immediate updates are unavailable, consider disabling Thunderbolt functionality via kernel parameters (e.g., modprobe.blacklist=thunderbolt) or physically disconnecting Thunderbolt devices until patched.

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