CVE-2026-74456 Linux CVE debrief

Who should care

Linux kernel developers and maintainers, Linux system administrators, and users of Linux-based systems should be aware of this vulnerability. They should review and apply the Linux kernel patch to fix the double-free vulnerability, inventory Linux systems using the affected kernel version, and monitor for potential exploitation attempts. Additionally, security teams and vulnerability management teams should prioritize this vulnerability and ensure that their systems are updated with the latest Linux kernel patch.

Technical summary

The vulnerability is caused by a double free of the transfer buffer in the peak_usb_start() function. When usb_submit_urb() fails, the error path frees the buffer explicitly with kfree(buf) and then calls usb_free_urb(urb). Because URB_FREE_BUFFER is set, usb_free_urb() -> urb_destroy() frees the same buffer a second time, resulting in a double free of the transfer buffer. This issue can be mitigated by applying the Linux kernel patch. Affected Linux kernel developers and maintainers should review and apply the patch, while Linux system administrators and users of Linux-based systems should inventory their systems and monitor for potential exploitation attempts.

Defensive priority

Medium

Recommended defensive actions

• Review and apply the Linux kernel patch to fix the double-free vulnerability
• Inventory Linux systems using the affected kernel version
• Monitor for potential exploitation attempts
• 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.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Evidence notes

The vulnerability was resolved in the Linux kernel. The bug was identified in the peak_usb_start() function, where a double free of the transfer buffer occurs on URB submit error. The issue was fixed by dropping the redundant kfree(buf) call, as usb_free_urb() already releases the transfer buffer. Further review of related code paths is recommended to ensure similar issues do not exist elsewhere. Defenders should verify that their Linux kernel versions have been updated to include this fix and monitor for potential exploitation attempts.

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.