CVE-2026-67303

mediumCVSS 4.3covered by 1 sourcefirst seen 2026-08-01

FreeRDP before 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == BytesReturned)) in serial_process_irp_device_control() in channels/serial/client/serial_main.c. When serial device redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing the mismatch to trigger the assertion and abort the client process (denial of service).

⚡ Watch CVE-2026-67303

Get an email if CVE-2026-67303 is added to CISA KEV, gains public exploit code, or a new advisory cites it — max one per day, one-click unsubscribe.

Advisory coverage (1)

mediumCVE-2026-67303: FreeRDP before 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == Bytes…nvd · 2026-08-01

External references

NVD record for CVE-2026-67303

CVE.org record

Embed the live status

— this badge updates automatically when the KEV or exploit status changes. How to embed it →

[![CVE-2026-67303 status](https://www.csirts.com/badge/CVE-2026-67303)](https://www.csirts.com/cve/CVE-2026-67303)