VulnerabilityPublished 14 May 2026

CVE-2026-45370: universal-tool-calling-protocol python-utcp · Cleartext Storage of Sensitive Information in an Environment Variable

Affects universal-tool-calling-protocol python-utcpSource CVE Database V5

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Mentioned vulnerabilities

CVE-2026-45369

Not known to be exploited · CVSS 7.7 High : upgrade to 1.1.2 soon.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

7.7High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.1.2, 1.1.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade python-utcp to 1.1.2; python-utcp to 1.1.3.

Affected software

Product	Affected	Fixed in
universal-tool-calling-protocolpython-utcp	Affected <1.1.2	Fixed in 1.1.2
PyPIpython-utcp`pkg:pypi/python-utcp`Other threats	Affected <1.1.3	Fixed in 1.1.3

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade python-utcp to version 1.1.3 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 1.1.3, applying this official update fully mitigates the issue. No additional mitigations are indicated.

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.

Impact

An attacker with the ability to invoke CLI subprocesses can access all environment variables containing sensitive information, potentially leading to the disclosure of secrets. The vulnerability does not impact integrity or availability but has a high confidentiality impact. No known exploits are reported in the wild at this time.

Summary

The vulnerability in python-utcp (universal-tool-calling-protocol) arises from the _prepare_environment() function in cli_communication_protocol.py passing a complete copy of os.environ to every CLI subprocess. This behavior causes sensitive environment variables to be exposed in cleartext to subprocesses, violating secure handling of secrets (CWE-526). The issue affects versions prior to 1.1.3 and can be exploited in conjunction with CVE-2026-45369 to exfiltrate all process-level secrets. The fix was introduced in version 1.1.3.

CWE-526Cleartext Storage of Sensitive Information in an Environment Variable (opens in a new tab)
Variant weaknessOWASP Top 10 A02:2025: Security Misconfiguration (opens in a new tab)
The product uses an environment variable to store unencrypted sensitive information.
Architecture and Design
Encrypt information stored in the environment variable to protect it from being exposed to an unauthorized user. If encryption is not feasible or is considered too expensive for the business use of the application, then consider using a properly protected configuration file instead of an environment variable.
Implementation
If the environment variable is not necessary for the desired behavior, then remove it entirely, or clear it to an empty value.
OWASP ASVS 4.0.3
V8.1.6 (opens in a new tab)
V8.2.3 (opens in a new tab)
V8.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-5v57-8rxj-3p2r (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 14 May 2026, 21:06 UTC

WeaknessesCWE-526

Technical details

References

Community reviews

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