CVE-2026-33633: Kitty has a Heap Buffer Overflow in its Graphics Protocol Handler

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-19 · updated 2026-07-24
Weakness: CWE-122

Description

Kitty is a cross-platform GPU based terminal. Versions 0.46.2 and below contain a heap buffer overflow in load_image_data() that allows any process which can write to the terminal's stdin to crash kitty immediately. The vulnerability is triggered by a single APC graphics protocol command with a PNG format declaration (f=100) whose payload exceeds twice the initial buffer capacity. The overflow is attacker-controlled in both length and content, causing DoS and potentially escalation to RCE itself. This issue has been fixed in version 0.47.0.

Affected products

kovidgoyal kitty: before 0.47.0 — fixed in 0.47.0

How to fix

Upgrade to a fixed version: kovidgoyal kitty 0.47.0. Check the vendor advisory for mitigations.

References

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