Shell command execution via auto-confirmed ZMODEM detection
Published May 15, 2026 · Updated May 15, 2026
OS command injection in Eugeny Tabby before 1.0.233 allows context-dependent attackers to execute shell commands via crafted terminal output. ZModemMiddleware feeds every output chunk to Zmodem.Sentry, unconditionally confirms a detected ZRQINIT header, and writes a fixed ZRINIT response into the active PTY. Execution requires a user to display attacker-controlled bytes while fish, bash, or zsh is active and an attacker-placed executable matches the resulting shell glob; the payload then runs with that user's privileges.
Summary
What happened
OS command injection in Eugeny Tabby before 1.0.233 allows context-dependent attackers to execute shell commands via crafted terminal output. ZModemMiddleware feeds every output chunk to Zmodem.Sentry, unconditionally confirms a detected ZRQINIT header, and writes a fixed ZRINIT response into the active PTY. Execution requires a user to display attacker-controlled bytes while fish, bash, or zsh is active and an attacker-placed executable matches the resulting shell glob; the payload then runs with that user's privileges.
The record
- CVE
- CVE-2026-45036
- Published
- May 15, 2026
- Updated
- May 15, 2026
- Vendor
- Russh Project
- Product
- Tabby
- Classifications
- CWE-78, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 15, 2026CVE publishedPublication date reported by the CVE source.
- May 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.0.233
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- ZMODEM PTY feedback reproduction harnessproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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