Authenticated token acceptance via incomplete JWT validation
Published May 26, 2026 · Updated May 26, 2026
Authentication bypass in Nuts Node before 5.4.31 or 6.0.0-alpha.1 through 6.2.2 allows remote authenticated users to replay VP JWTs. IntrospectAccessToken performs only standard JWT checks, ignores the vp claim during lenient JSON unmarshaling, and omits type, issuer-key, and service validation. Exploitation requires a short-lived VP received during a legitimate v1 flow; strict resource servers reject its empty service and issuer, limiting practical access.
Summary
What happened
Authentication bypass in Nuts Node before 5.4.31 or 6.0.0-alpha.1 through 6.2.2 allows remote authenticated users to replay VP JWTs. IntrospectAccessToken performs only standard JWT checks, ignores the vp claim during lenient JSON unmarshaling, and omits type, issuer-key, and service validation. Exploitation requires a short-lived VP received during a legitimate v1 flow; strict resource servers reject its empty service and issuer, limiting practical access.
The record
- CVE
- CVE-2026-41164
- Published
- May 26, 2026
- Updated
- May 26, 2026
- Vendor
- Stichting Nuts
- Product
- Nuts Node
- Classifications
- CWE-345, T1550.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 26, 2026CVE publishedPublication date reported by the CVE source.
- May 26, 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=< 5.4.31
- Affected versionversion=>= 6.0.0-alpha.1, < 6.2.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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