Account takeover via prefix-matched OAuth origins
Published Feb 21, 2026 · Updated Feb 21, 2026
Origin validation error in FeathersJS Feathers 5.0.39 and earlier allows remote attackers to hijack accounts through OAuth token theft. The getAllowedOrigin function accepts a Referer when its lowercased value merely starts with an allowed origin, so attacker-controlled suffixes pass. Exploitation requires a configured origins array, a prefix-sharing domain, and an OAuth flow that exposes the redirected token.
Summary
What happened
Origin validation error in FeathersJS Feathers 5.0.39 and earlier allows remote attackers to hijack accounts through OAuth token theft. The getAllowedOrigin function accepts a Referer when its lowercased value merely starts with an allowed origin, so attacker-controlled suffixes pass. Exploitation requires a configured origins array, a prefix-sharing domain, and an OAuth flow that exposes the redirected token.
The record
- CVE
- CVE-2026-27192
- Published
- Feb 21, 2026
- Updated
- Feb 21, 2026
- Vendor
- FeathersJS
- Product
- Feathers
- Classifications
- CWE-346, CAPEC-21, T1528
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 21, 2026CVE publishedPublication date reported by the CVE source.
- Feb 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 5.0.40
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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