Authentication bypass via missing HMAC secret
Published Dec 4, 2025 · Updated Dec 5, 2025
Improper HMAC verification in Auth0 node-jws 3.2.2 and earlier and 4.0.0 allows remote attackers to bypass signature checks. VerifyStream converts an undefined secret returned by a protected-header or payload lookup into empty input, allowing an attacker-signed HS256 value made with an empty secret to validate. Exposure requires createVerify(), an HMAC algorithm, and attacker-controlled lookup data; synchronous verify(), asymmetric algorithms, and lookups independent of JWS content are unaffected.
Summary
What happened
Improper HMAC verification in Auth0 node-jws 3.2.2 and earlier and 4.0.0 allows remote attackers to bypass signature checks. VerifyStream converts an undefined secret returned by a protected-header or payload lookup into empty input, allowing an attacker-signed HS256 value made with an empty secret to validate. Exposure requires createVerify(), an HMAC algorithm, and attacker-controlled lookup data; synchronous verify(), asymmetric algorithms, and lookups independent of JWS content are unaffected.
The record
- CVE
- CVE-2025-65945
- Published
- Dec 4, 2025
- Updated
- Dec 5, 2025
- Vendor
- Auth0
- Product
- node-jws
- Classifications
- CWE-347
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 4, 2025CVE publishedPublication date reported by the CVE source.
- Dec 5, 2025Record 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=< 3.2.3
- Affected versionversion=>= 4.0.0, <= 4.0.1
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
- CVE-2025-65945 node-jws signature-bypass PoCproof of concept · unverified
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Technologies
Your stack
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Your stack
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