CVE-2025-14542 Universal Tool Calling Protocol (UTCP) client library for Python vulnerable to Trust Boundary Violation through Manual JSON specification
Attackers can achieve remote code execution by serving a malicious Manual specification to clients fetching tools from a remote endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-14542?
CVE-2025-14542 is a high-severity command injection vulnerability in utcp, published on 13 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
The vulnerability arises when a client fetches a tools’ JSON specification, known as a Manual, from a remote Manual Endpoint. While a provider may initially serve a benign manual (e.g., one defining an HTTP tool call), earning the clients’ trust, a malicious provider can later change the manual to exploit the client.
Weakness: CWE-501
Which versions are affected by CVE-2025-14542?
3 open source packages ship an affected version, including utcp.
| Package | Affected | Fixed in |
|---|---|---|
utcp PyPI | All versions | 1.1.0 |
utcp PyPI | All versions | 1.1.0 |
utcp PyPI | All versions | 1.1.0 |
How do I fix CVE-2025-14542?
Upgrade utcp to 1.1.0 or later.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2025-14542 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-14542 exists.
Sources
Also known as GHSA-75mj-4g74-9rg2, PYSEC-2026-2000.