CVE-2026-45366 json
typescript-utcp: SSRF via attacker-controlled OpenAPI servers[0].url in HTTP communication protocol
published 5mo ago modified last mo. also GHSA-r8j5-8747-88cm , EUVD-2026-33053
- cvss
- 4.7
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.1%
- EPSS 0.1% chance of exploitation in 30 days, percentile 2%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm @utcp/http 1.1.2
Is CVE-2026-45366 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.12% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N |
| GitHub | 3.1 | 4.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @utcp/http | <1.1.2 |
1.1.2 |
Affected products
- universal-tool-calling-protocol typescript-utcp
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
Sources
- CVE List CVE-2026-45366
- GitHub Advisory GHSA-r8j5-8747-88cm
- NVD CVE-2026-45366
Fencer Intel 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.