CVE-2026-50256

The CVE affects the X.Org X server and Xwayland. A mismatch between the server and libXfont2 regarding maximum font name length (server-allocated 256-byte stack buffer vs libXfont2 name length up to 1024 bytes) allows a font alias name of 257–1023 bytes to overflow the stack during alias resoluti...

CVE-2026-50256 Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias...