CVE-2026-33642
Description
Kitty is a cross-platform GPU based terminal. In versions 0.46.2 and below, the handle_compose_command() 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 x_offset/y_offset values that pass the bounds check after wrapping but cause massive out-of-bounds heap memory access in compose_rectangles(). 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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-33642
Vendor advisory: security-advisories@github.com — https://github.com/kovidgoyal/kitty/security/advisories/GHSA-qfgm-2c64-6x3x
Vendor advisory: security-advisories@github.com — https://github.com/kovidgoyal/kitty/commit/e9661f0f3afb4e4dbffa509adfb3df3c9780ad34
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| debian | bookworm | affected | |
| debian | bullseye | fixed | 0 |
| debian | forky | fixed | 0.47.0-1 |
| debian | sid | fixed | 0.47.0-1 |
| debian | trixie | affected | |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| kovidgoyal | kitty | {"endExcluding":"0.47.0"} | 0.47.0 |
References
CWEs
CWE-125 CWE-190 CWE-787
Verify integrity in audit chain (admin only). AS-IS.