CVE-2026-114043

A flaw was found in FreeRDP. WinPR's clipboard PNG-to-CF_DIB synthesis allocates a bit-packed buffer for PNGs with bit depth below 8, while winpr_bitmap_write_buffer() copies rows assuming one byte per pixel. A malicious RDP server can send a crafted low-bit-depth PNG clipboard payload that, when pasted by the victim, discloses heap memory. This issue affects FreeRDP before 3.32.1 when WINPR_UTILS_IMAGE_PNG is enabled.

This issue is rated Moderate because a user must connect to a malicious RDP server and paste or otherwise retrieve the crafted clipboard image (UI:R). The impact is high confidentiality disclosure of adjacent heap memory, without integrity or availability impact in the assessed scenario. The vulnerable path requires WinPR PNG clipboard conversion (WINPR_UTILS_IMAGE_PNG), introduced in FreeRDP/WinPR 3.x. Red Hat Enterprise Linux 8 and 9 ship FreeRDP 2.x without this code path and are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Do not connect FreeRDP clients to untrusted RDP servers, and avoid pasting remote clipboard image content from untrusted sessions. If clipboard redirection is unused, disable the CLIPRDR channel.