CVE-2026-33642CWE-125CWE-190CWE-787

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

Critical · published May 19, 2026

CVSS v3.1
9.9
EPSS
0%
Percentile
36.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.9 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H
CVSS v4.0
Not supplied
EPSS
0.00434 · 36.6th percentile
Weaknesses
CWE-125 · Out-of-bounds Read; CWE-190 · Integer Overflow or Wraparound; CWE-787 · Out-of-bounds Write
Published
2026-05-19T18:04Z
EPSS history
Timeline
  • 19 MAY 18:04Z
    Kitty has a Heap Buffer Over-Read/Write via Integer Overflow in compose_rectangles Bounds Check
    cvelistv5