CVE-2026-45370 python-utcp: Full Process Environment Exposed to CLI Subprocess - Secrets Leakage via Command Injection
Attackers can exfiltrate process-level secrets from CLI subprocesses due to full environment variable exposure in the python-utcp library.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-45370?
CVE-2026-45370 is a high-severity vulnerability in universal-tool-calling-protocol python-utcp, published on 14 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
python-utcp is the python implementation of UTCP. Prior to 1.1.3, _prepare_environment() in cli_communication_protocol.py passes a full copy of os.environ to every CLI subprocess. When combined with CVE-2026-45369, an attacker can exfiltrate all process-level secrets in a single tool call. This vulnerability is fixed in 1.1.3.
Weakness: CWE-526
Which versions are affected by CVE-2026-45370?
3 open source packages ship an affected version, including utcp-cli.
| Package | Affected | Fixed in |
|---|---|---|
utcp-cli PyPI | All versions | 1.1.2 |
utcp-cli PyPI | All versions | 1.1.2 |
utcp-cli PyPI | All versions | 1.1.2 |
How do I fix CVE-2026-45370?
Upgrade utcp-cli to 1.1.2 or later.
Is CVE-2026-45370 being exploited?
There is no known exploitation of CVE-2026-45370 in the wild and no public exploit code.
Sources
Also known as GHSA-5v57-8rxj-3p2r, PYSEC-2026-3395.