High [CVE-2026-63958] validate connector number in ucsi_connector_change
This high-severity Red Hat Linux advisory covers CVE-2026-63958 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8.
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Summary
In the Linux kernel, the following vulnerability has been resolved: usb: typec: ucsi: validate connector number in ucsi_connector_change() The connector number in a UCSI CCI notification is a 7-bit field supplied by the PPM. ucsi_connector_change() uses it to index the ucsi->connector[] array without checking it against the number of connectors the PPM reported at init time, so a buggy or malicious PPM (EC firmware, or an I2C-attached UCSI controller on the ccg / stm32g0 / glink transports) can drive schedule_work() on memory past the end of the array.
Reject connector numbers that are zero or exceed cap.num_connectors before dereferencing the array. A flaw was found in the Linux kernel's USB Type-C subsystem.
This vulnerability allows a malicious or buggy Power Delivery Microcontroller (PPM), such as embedded controller (EC) firmware or an I2C-attached Universal Serial Bus (USB) Type-C Connector System Interface (UCSI) controller, to provide an invalid connector number.
This invalid number is then used to access memory beyond the intended array boundaries, which can lead to a system crash. The primary consequence is a denial of service, making the system unavailable.
Red Hat severity: Moderate — CVSS 7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H). Weakness: CWE-787.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
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