CVE-2026-33642: Kitty has a Heap Buffer Over-Read/Write via Integer Overflow in compose_rectangles Bounds Check

Kitty is a cross-platform GPU based terminal. In versions 0.46.2 and below, the handlecomposecommand() function in kitty/graphics.c performs bounds validation on composition offsets using unsigned 32-bit arithmetic that is subject to integer wrapping, potentially leading to Heap Buffer Over-Read/Write. An attacker who can write escape sequences to a kitty terminal (e.g., via a malicious file, SSH login banner, or piped content) can supply crafted xoffset/yoffset values that pass the bounds check after wrapping but cause massive out-of-bounds heap memory access in composerectangles(). No user interaction is required. No non-default configuration is required. The attacker only needs the ability to produce output in a kitty terminal window. This issue has been fixed in version 0.47.0.