@utcp/http: SSRF via attacker-controlled OpenAPI servers[0].url in HTTP communication protocol

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-45366: 0.12% estimated exploitation activity in the next 30 days; percentile 2.00 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. A separate prefix-bypass also affected the discovery-time check: the previous startsWith('http://localhost') guard let URLs like http://localhost.evil.com through. Sister advisory This is the npm/TypeScript counterpart of GHSA-39j6-4867-gg4w / CVE-2026-44661 on the Python…

Published by the source

14 May 2026, 20:55 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 12:53 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-r8j5-8747-88cm

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-r8j5-8747-88cm

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# Patch Next advisory brief: CVE-2026-45366

Advisory: @utcp/http: SSRF via attacker-controlled OpenAPI servers[0].url in HTTP communication protocol
IDs: CVE-2026-45366, GHSA-r8j5-8747-88cm
Record: https://patchnext.com/advisories/cve-2026-45366 (revision 2, source checked 26 Oct 2026, 12:53 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @utcp/http 1.1.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @utcp/http: affected <= 1.1.1; fixed in 1.1.2

## Suggested inspection (read-only)
- `npm ls @utcp/http --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @utcp/http.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-r8j5-8747-88cm (OSV record GHSA-r8j5-8747-88cm lists affected ranges: npm @utcp/http >=0 <1.1.2 (fixed))
- Verified: https://github.com/advisories/GHSA-r8j5-8747-88cm (GitHub-reviewed advisory GHSA-r8j5-8747-88cm lists affected ranges: npm @utcp/http >=0 <=1.1.1)

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