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Fencer Vulns
high 8.3

CVE-2026-45369 json

python-utcp: Command Injection via Unsanitized Argument Substitution in CLI Communication Protocol

published 2026-05-14 5 mo ago modified 2026-10-26 13 d ago also GHSA-33p6-5jxp-p3x4 , PYSEC-2026-560 , EUVD-2026-30475

cvss
8.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

python-utcp is the python implementation of UTCP. Prior to 1.1.3, the _substitute_utcp_args method in cli_communication_protocol.py inserts user-controlled tool_args values directly into shell command strings without any sanitization or escaping. These commands are then executed via /bin/bash -c (Unix) or powershell.exe -Command (Windows), allowing an attacker to inject arbitrary shell commands. This vulnerability is fixed in 1.1.3.

Patch / fix

  • pypi utcp-cli 1.1.2

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
5 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-33p6-5jxp-p3x4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.3 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
OSV 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
GitHub 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi utcp-cli
<1.1.2
1.1.2

Affected products

  • universal-tool-calling-protocol python-utcp

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.