CVE intelligence and bounded remediation

CVE-2026-27191 — Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript

High CVSS 7.4

Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. Versions 5.0.39 and below the redirect query parameter is appended to the base origin without validation, allowing attackers to steal access tokens via URL authority injection. This leads to full account takeover, as the attacker obtains the victim's access token and can impersonate them. The application constructs the final redirect URL by concatenating the base origin with the user-supplied redirect parameter. This is exploitable when the origins array is configured and origin values do not end with /. An attacker can supply @attacker.com as the redirect value results in https://target.com@attacker.com#access_token=..., where the browser interprets attacker.com as the host, leading to full account takeover. This issue has been fixed in version 5.0.40.

Severity
High
CVSS
7.4 (4.0)
Published
2026-02-21
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-601

Affected products

  • feathersjs / feathers

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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