CVE-2026-67301
HIGHFreeRDP before 3.29.0 contains out-of-bounds read vulnerabilities in the async update message proxy for the PolygonSC and PolygonCB primary drawing orders. When AsyncUpdate is enabled (e.g., xfreerdp /async-update), update_message_PolygonSC() and update_message_PolygonCB() allocate a fresh points array but copy point data from the address of the order structure instead of from polygonSC->points / polygonCB->points, resulting in a client-side out-of-bounds read. A malicious or compromised RDP server sending crafted PolygonSC/PolygonCB update orders can trigger memory disclosure or a client crash.
Published: 8/1/2026Modified: 8/3/2026
References (4)
https://github.com/FreeRDP/FreeRDP/commit/5370fb26fbf034ecd11d3026b6ad639b5fff493fhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vxp3-7g6q-rq2whttps://www.vulncheck.com/advisories/freerdp-before-out-of-bounds-read-via-polygon-async-message-proxyhttps://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vxp3-7g6q-rq2w