CVE-2026-98771: Linux Vulnerability

Description

In the Linux kernel, the following vulnerability has been resolved: usb: storage: sierra_ms: reject short SWoC info transfers sierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes from the device via usb_control_msg(), but its callers only treat a negative return value as failure. A device that answers the vendor-specific GetSwocInfo request with a short IN transfer is therefore accepted, leaving the tail of the freshly allocated (kmalloc(), non-zeroing) swoc_info buffer uninitialized. truinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU and swocInfo->LinuxVer from that buffer into the world-readable (0444) "truinst" sysfs attribute. An emulated/malicious USB device (VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes of stale kernel heap memory (kmalloc-64) to unprivileged userspace, once per sysfs read, indefinitely. On kernels built without init_on_alloc this leaks recently freed heap contents. Only accept the transfer when the full structure was received. sierra_ms_init() already retries failed queries, so well-behaved devices are unaffected.

Metrics

EPSS Probability

0.17%

6.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 32fe5e393455d87db4988af03915634304870fb4, < 353ca2623104a3baf5642c3ea31569df04ce4aaf; >= 32fe5e393455d87db4988af03915634304870fb4, < 799810166646bcf9dc5a4e77bc4b0bdf6bc443f2; >= 32fe5e393455d87db4988af03915634304870fb4, < 411da2ec8c62bfa39407e5a20d659b973b3cf311; >= 32fe5e393455d87db4988af03915634304870fb4, < 4faaad69f18332246bbd4ca41718beb2a305bb72; >= 32fe5e393455d87db4988af03915634304870fb4, < c85e8331d298b8f1dee8fe63718e76435cec7133; >= 32fe5e393455d87db4988af03915634304870fb4, < e2d62928f2666a2964a23b1d39e6e762f0628d7b; >= 32fe5e393455d87db4988af03915634304870fb4, < db9d3be156baca6ef80ae5d93acfeb85c61a74dd; >= 32fe5e393455d87db4988af03915634304870fb4, < 8a0200d14acd9db388b85cd016e68a4e60d900ec
Linux	Linux	2.6.27

References

Timeline

Published: Oct 18, 2026
Last Modified: Oct 30, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-98771?

In the Linux kernel, the following vulnerability has been resolved: usb: storage: sierra_ms: reject short SWoC info transfers sierra_get_swoc_info() requests sizeof(struct swoc_info) (60) bytes from the device via usb_control_msg(), but its callers only treat a negative return value as failure. A device that answers the vendor-specific GetSwocInfo request with a short IN transfer is therefore accepted, leaving the tail of the freshly allocated (kmalloc(), non-zeroing) swoc_info buffer uninitialized. truinst_show() subsequently prints swocInfo->rev, swocInfo->LinuxSKU and swocInfo->LinuxVer from that buffer into the world-readable (0444) "truinst" sysfs attribute. An emulated/malicious USB device (VID 0x1199, PID 0x0fff) can exploit this to disclose up to 5 bytes of stale kernel heap memory (kmalloc-64) to unprivileged userspace, once per sysfs read, indefinitely. On kernels built without init_on_alloc this leaks recently freed heap contents. Only accept the transfer when the full structure was received. sierra_ms_init() already retries failed queries, so well-behaved devices are unaffected.

How severe is CVE-2026-98771?

Severity scoring for CVE-2026-98771 is pending analysis. The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.

How do I fix CVE-2026-98771?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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