CVE-2026-63958 Linux CVE debrief

Who should care

Linux kernel users and administrators should review and apply patches for this vulnerability. They should also verify the number of connectors reported by the PPM at init time and monitor for potential malicious activity.

Technical summary

The Linux kernel vulnerability CVE-2026-63958 is related to the usb: typec: ucsi module. 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. This allows a buggy or malicious PPM to drive schedule_work() on memory past the end of the array. Linux kernel users should review and apply patches for this vulnerability.

Defensive priority

High priority for Linux kernel users and administrators to apply patches

Recommended defensive actions

• Review and apply patches for the Linux kernel vulnerability CVE-2026-63958
• Verify the number of connectors reported by the PPM at init time
• Monitor for potential malicious activity
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-19T16:17:14.667Z and has not been modified since then. The NVD entry is currently Received. Linux kernel users should verify the number of connectors reported by the PPM at init time and monitor for potential malicious activity.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.