typescript-utcp: SSRF via attacker-controlled OpenAPI servers[0].url in HTTP communication protocol
Published May 28, 2026
4.7
MEDIUMCVSS 3.1
EPSS 0.20%
Description
typescript-utcp is a typescript implementation of UTCP. Prior to 1.1.2, the @utcp/http package is vulnerable to a blind Server-Side Request Forgery (SSRF) caused by a trust-boundary inconsistency between manual discovery and tool invocation. registerManual() validates the discovery URL against an HTTPS / loopback allowlist, but callTool() reuses the resolved toolCallTemplate.url directly without revalidating, and the OpenApiConverter blindly trusts whatever servers[0].url an attacker-hosted spec declares. An attacker who hosts a malicious OpenAPI spec on a legitimate HTTPS endpoint can declare e.g. servers: [{ url: "http://127.0.0.1:9090" }] or servers: [{ url: "http://169.254.169.254" }]; the converter then produces tools whose URL points at internal services on the agent host. This vulnerability is fixed in 1.1.2.
Affected products
-
- Version < 1.1.2StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Universal-Tool-Calling-Protocol | Typescript-Utcp | n/a |
|
No data.
No data.
No Red Hat product state for this CVE.
@utcp/http
npm
Introduced 0 Fixed 1.1.2
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| npm | @utcp/http | 0 | 1.1.2 |
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed May 29, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
May–Oct 2026- EPSS v4
- EPSS v5
Percentile over time
- EPSS v4
- EPSS v5
Table of values (3 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.20% (0.00196) | 8.32th | v5 (v2026.06.15) |
| Jun 15, 2026 | 0.12% (0.00122) | 2.32th | v5 (v2026.06.15) |
| May 29, 2026 | 0.03% (0.00027) | 8.13th | v4 (v2025.03.14) |
References (4)
- https://github.com/advisories/GHSA-r8j5-8747-88cm Advisory
- https://github.com/universal-tool-calling-protocol/python-utcp/issues/83
- https://github.com/universal-tool-calling-protocol/typescript-utcp/security/advisories/GHSA-r8j5-8747-88cm x_refsource_CONFIRM
- https://nvd.nist.gov/vuln/detail/CVE-2026-45366
Change history (0)
No recorded changes yet.