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CVE-2026-27192: Feathersjs Feathers Security Vulnerability (CVSS 7.6)

CVE-2026-27192 is a high severity security vulnerability in Feathersjs Feathers with a CVSS score of 7.6. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Last updated: Jun 17, 2026

Quick answer

Direct answer

CVE-2026-27192 is a high severity security vulnerability in Feathersjs Feathers with a CVSS score of 7.6. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Risk scores

CVSS base score
7.6HIGH
EPSS probability
0.31%
Higher than 22 percent of all CVEs
CISA KEV
Not listed
CVSS metricWhat it means
Attack vector (AV:N)Network: reachable remotely
Attack complexity (AC:H)High complexity
Attack requirements (AT:N)No attack requirements
Privileges required (PR:N)No privileges required
User interaction (UI:P)Passive user interaction
Confidentiality (VC:H)High confidentiality impact
Integrity (VI:H)High integrity impact
Availability (VA:N)No availability impact

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/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

About Feathersjs Feathers

CVE-2026-27192 affects Feathersjs Feathers, a product from Feathersjs. Before acting, confirm where Feathersjs Feathers runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.

What the flaw is

In plain terms: Feathersjs is a framework for creating web APIs and real-time applications with TypeScript or JavaScript. In versions 5.0.39 and below, origin validation uses startsWith() for comparison, allowing attackers to bypass the check by registering a domain that shares a common prefix with an allowed origin.The getAllowedOrigin() function checks if the Referer header starts with any allowed origin, and this comparison is insufficient as it only validates the prefix. This is exploitable when the origins array is configured and an attacker registers a domain starting with an allowed origin string (e.g., https://target.com.attacker.com bypasses https://target.com). On its own, tokens are still redirected to a configured origin. However, in specific scenarios an attacker can initiate the OAuth flow from an unauthorized origin and exfiltrate tokens, achieving full account takeover. This issue has bee fixed in version 5.0.40.

Based on its CVSS vector, the flaw can be reached over the network, needs no login, and relies on a user taking an action. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

Affected versions and timeline

FieldDetail
ProductFeathersjs Feathers
Affected versionsFeathers before 5.0.40
PublishedFeb 21, 2026
Last modifiedJun 17, 2026
Added to CISA KEVNot listed
Assigning CNAsecurity-advisories@github.com

How to detect it

  • Inventory every instance of Feathersjs Feathers and record the running version against the affected range above.
  • Check external attack surface scans for internet facing instances of the component.
  • Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
  • Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.

How to fix it

  • Apply the fixed version of Feathersjs Feathers named in the vendor advisory.
  • If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
  • Rescan after the change to prove the exposure is gone, then close the ticket.

CTEM action plan

CTEM stageWhat to do for this CVE
ScopeAdd every business service that depends on Feathersjs Feathers to the current CTEM cycle.
DiscoverFind all instances, including shadow and cloud deployments, and record versions and exposure.
PrioritizeRank using EPSS and CVSS together with asset exposure and business impact.
ValidateConfirm the flaw is reachable and exploitable in your environment and that compensating controls work.
MobilizeAssign the fix to the asset owner with a due date matched to the priority, then verify closure.

CWE References

Technical References

Frequently asked questions

CVE-2026-27192 is a high severity security vulnerability in Feathersjs Feathers with a CVSS score of 7.6. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.

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