VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98771: Linux kernel · usb: storage: sierra_ms: reject short SWoC info transfers

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in e2d62928f2666a2964a23b1d39e6e762f0628d7b : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in e2d62928f2666a2964a23b1d39e6e762f0628d7b, db9d3be156baca6ef80ae5d93acfeb85c61a74dd, c85e8331d298b8f1dee8fe63718e76435cec7133 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 32fe5e393455d87db4988af03915634304870fb4, < e2d62928f2666a2964a23b1d39e6e762f0628d7b	Fixed in e2d62928f2666a2964a23b1d39e6e762f0628d7b
LinuxLinux	Affected ≥ 32fe5e393455d87db4988af03915634304870fb4, < db9d3be156baca6ef80ae5d93acfeb85c61a74dd	Fixed in db9d3be156baca6ef80ae5d93acfeb85c61a74dd
LinuxLinux	Affected ≥ 32fe5e393455d87db4988af03915634304870fb4, < c85e8331d298b8f1dee8fe63718e76435cec7133	Fixed in c85e8331d298b8f1dee8fe63718e76435cec7133
LinuxLinux	Affected ≥ 32fe5e393455d87db4988af03915634304870fb4, < 8a0200d14acd9db388b85cd016e68a4e60d900ec	Fixed in 8a0200d14acd9db388b85cd016e68a4e60d900ec
LinuxLinux	Affected ≥ 32fe5e393455d87db4988af03915634304870fb4, < 4faaad69f18332246bbd4ca41718beb2a305bb72	Fixed in 4faaad69f18332246bbd4ca41718beb2a305bb72
LinuxLinux	Affected =2.6.27	Fixed in–

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.

References

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