Published At-15 May, 2026 | 17:16
Updated At-20 May, 2026 | 17:16
Tabby (formerly Terminus) is a highly configurable terminal emulator. Prior to 1.0.233, Tabby before 1.0.233 automatically confirms ZMODEM protocol detection on all terminal session output without user interaction, enabling shell command execution when a user displays attacker-controlled content. The ZModemMiddleware in tabby-terminal consumes all session output through a Zmodem.Sentry, and when a ZMODEM ZRQINIT header is detected, unconditionally calls detection.confirm() and writes a fixed ZRINIT response ( **\x18B0100000023be50\r\n\x11) back into the active PTY as input. When the process that triggered the detection (e.g., cat) exits, the injected bytes are consumed by the user's shell as a command line. Under fish (default configuration), the ** prefix triggers recursive glob expansion against the current directory, allowing an attacker-placed executable at a matching nested path (e.g., d/xB0100000023be50) to be executed by relative pathname without relying on PATH. Under bash and zsh, a secondary xterm.js terminal color-query feedback (OSC 10) can be combined in the same file to inject a slash-containing command word that similarly bypasses PATH resolution. An attacker can exploit this by providing a crafted file (e.g., in a cloned Git repository) that a user displays with cat, achieving code execution with no interaction beyond viewing the file. This vulnerability is fixed in 1.0.233.
CISA Catalog
| Date Added | Due Date | Vulnerability Name | Required Action |
|---|
| N/A | | |
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
| Type | Version | Base score | Base severity | Vector |
|---|
| Secondary | 3.1 | 7.0 | HIGH | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
| Primary | 3.1 | 7.0 | HIGH | CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H |
Type: Secondary
Version: 3.1
Base score: 7.0
Base severity: HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Type: Primary
Version: 3.1
Base score: 7.0
Base severity: HIGH
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Weaknesses
| CWE ID | Type | Source |
|---|
| CWE-78 | Secondary | security-advisories@github.com |
Type: Secondary
Source: security-advisories@github.com
Change History
0Changes found