CVE-2026-27191

7.4 HIGH 0.3% exploit odds Fix listed Other Web app

What it is

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://[email protected]#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.

At a glance

Exploitability: Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-02-21 04:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 10:26 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.3% in the next 30 days (EPSS).
Severity: 7.4 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-02-21 04:15 UTC
Last modified: 2026-06-17 10:26 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-601
Record status: Analyzed

Affected

Feathersjs Feathers < 5.0.40

Attack profile CVSS 4.0 · 7.4

Attack vector: Network
Complexity: High
Attack requirements: Present
Privileges needed: None
User interaction: Active
Confidentiality: High
Integrity: High
Availability: None

Raw vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-27191.md and follow it. Check whether this project is affected by CVE-2026-27191. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record