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

Routine

MEDIUM 6.1UPGRADE

CVE-2026-27191 is a medium-severity flaw (CVSS 6.1) affecting feathers. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 c

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.3% (top 78%)
CISA exploited list	No
Weakness	CWE-601
Published	2026-02-21
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: feathersjs

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-02-21 04:15 UTCPublished CVE record published
2026-06-17 10:26 UTCUpdated Record last modified

feathersjs feathers UPGRADE

Affected: < 5.0.40

Fixed in: 5.0.40

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls feathers

2. UPGRADE to 5.0.40

npm install feathers@">=5.0.40"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-27191?

feathers: upgrade to 5.0.40. Exact commands for each OS are on this page.

Is CVE-2026-27191 being exploited?

CVE-2026-27191 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-27191 affect?

CVE-2026-27191 affects feathers. Severity is medium (CVSS 6.1). 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

How urgent is CVE-2026-27191?

Priority 27/100. No elevated risk signals yet.

Related CVEs

CVE-2026-29793 CRITICAL 9.8 UPGRADE Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript
CVE-2026-29792 CRITICAL 9.8 UPGRADE Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript
CVE-2026-27193 MEDIUM 5.3 UPGRADE Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript
CVE-2026-27192 HIGH 8.1 UPGRADE Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript

References

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