VulnerabilityPublished 19 Jul 2026

CVE-2026-63958: Linux kernel · usb: typec: ucsi: validate connector number in ucsi_connector_change()

Affects Linux kernelSource GCVE Database

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Not known to be exploited.

Data as of 30 Oct 2026, 15:48 UTC

Severity

High

Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

AI-suggested

A fix is available that validates connector numbers before accessing the ucsi->connector[] array, rejecting invalid values. Users should apply the official Linux kernel updates that include this validation. No additional mitigations are indicated.

Description

A vulnerability in the Linux kernel's USB Type-C UCSI driver allows improper validation of connector numbers in the ucsi_connector_change() function. This flaw permits a buggy or malicious Platform Policy Manager (PPM) to cause out-of-bounds array access by supplying connector numbers that are zero or exceed the number of connectors reported at initialization.

Impact

This vulnerability could allow a malicious or buggy PPM to trigger out-of-bounds memory access in the kernel, potentially leading to undefined behavior such as memory corruption or kernel crashes. The description does not specify exploitation in the wild or direct privilege escalation, but the flaw could be leveraged for denial of service or other kernel-level impacts.

Summary

The Linux kernel's USB Type-C UCSI driver did not validate the connector number field in UCSI CCI notifications before using it to index the ucsi->connector[] array. The connector number is a 7-bit field provided by the PPM. Without proper bounds checking, a malicious or faulty PPM (such as EC firmware or an I2C-attached UCSI controller on certain transports) could cause schedule_work() to be called on memory beyond the array's end. The vulnerability is addressed by rejecting connector numbers that are zero or exceed the cap.num_connectors value before dereferencing the array.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 30 Oct 2026, 15:48 UTC

Technical details

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