CVE-2026-85660 cli-mcp-server 0.2.5 Command Allowlist Bypass via Shell Substitution
Attackers can bypass command allowlists to execute arbitrary commands when shell operators are enabled in cli-mcp-server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85660?
CVE-2026-85660 is a critical command injection vulnerability in MladenSU cli-mcp-server, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
cli-mcp-server 0.2.5 contains a command allowlist bypass vulnerability in the _validate_command_with_operators function when ALLOW_SHELL_OPERATORS is enabled. Attackers can use shell command substitution syntax like $(...) or backticks to execute non-allowlisted commands that bypass the ALLOWED_COMMANDS validation check.
Weakness: CWE-78
Which versions are affected by CVE-2026-85660?
How do I fix CVE-2026-85660?
No fix has been published for CVE-2026-85660 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-85660 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85660 exists.
Sources
Also known as GHSA-wfpw-4v5h-6h32.