CVE-2026-95832: Reflected unknown field names in the kitty colour control escape code allow command execution in the user's shell
Improper Neutralization of Special Elements in Output Used by a Downstream Component in the colour control escape code handler in kitty from 0.47.3 before 0.49.0 allows a program writing to the terminal to execute an arbitrary command in the user's shell, because colorcontrol() in kitty/window.py answers a query for an unrecognised field name by placing that field name into the reply, and writeescapecodetochild() in kitty/screen.c then writes the reply to the pseudoterminal master, where it is not distinguishable from input typed by the user, without neutralising it for the shell that reads it. The payload is reduced to printable ASCII before the field name is echoed, which is the restriction introduced in 0.47.3 as the fix for CVE-2026-54057, and the record and field separators ; and = are consumed as delimiters, but every other printable character survives, which is sufficient to compose a shell command. A newline is available from handleremotessh() in kitty/window.py, which writes the bytes yielded by getsshdata() in kittens/ssh/utils.py, the first of which begin with a newline, to the pseudoterminal master before any credential carried in the request is checked. The reply is framed as an OSC sequence carrying the escape code number, the field name, and the literal value ?. This results in execution of an attacker-chosen command with the privileges of the user running the terminal.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
kittyto a version that resolves this vulnerability.Fixed in 0.49.0
Event History
Frequently Asked Questions
Which installations should be treated as affected?
kitty versions from 0.47.3 up to, but not including, 0.49.0 are affected. Version 0.49.0 is identified as the fixed release.
What access does an attacker need to trigger this?
An attacker needs to cause a program to write crafted escape sequences to the victim's kitty terminal. The resulting reply is written to the pseudoterminal master and can be interpreted as user input by the shell.
Does the printable-ASCII filtering prevent exploitation?
No. Although the reflected field name is reduced to printable ASCII and semicolons and equals signs are consumed as delimiters, the remaining printable characters are sufficient to construct a shell command.
How can I determine whether a system is at risk?
Check the installed kitty version and whether users run programs that can write untrusted content or escape sequences to their terminal. Systems running an affected version in that scenario should be considered exposed.