CVE-2026-63904: usb: usbtmc: check URB actual_length for interrupt-IN notifications

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-19 · updated 2026-10-30
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: usb: usbtmc: check URB actual_length for interrupt-IN notifications USBTMC devices can use an optional interrupt endpoint for notification messages. These typically contain two-byte headers indicating the payload format, but the driver does not check if these headers are present before accessing the data buffers. In cases where the URB actual_length is not enough to fit these headers, the driver will either cause an out-of-bounds read, or consume stale leftover data from a previous notification. Fix by checking if actual_data contains enough bytes for the headers, otherwise resubmit URB to the interrupt endpoint.

Affected products

Linux kernel: from 4.6 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.93; from 6.13 before 6.18.35 — fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35
Linux kernel: 4.6 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 5.10.259, 5.15.210, 6.1.176, 6.6.143; Linux kernel 7.1. Check the vendor advisory for mitigations.

References

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