Account enumeration via skipped Argon2 hashing
Published Feb 2, 2026 · Updated Feb 2, 2026
Information disclosure in PolarLearn 0-PRERELEASE-15 and earlier allows remote attackers to enumerate accounts through sign-in timing. The signInCredentials function returns before Argon2 hashing when no database user matches the email, while existing users trigger the expensive hash and a measurable delay. No authentication or user interaction is required; successful probing reveals only whether a supplied email address has an account.
Summary
What happened
Information disclosure in PolarLearn 0-PRERELEASE-15 and earlier allows remote attackers to enumerate accounts through sign-in timing. The signInCredentials function returns before Argon2 hashing when no database user matches the email, while existing users trigger the expensive hash and a measurable delay. No authentication or user interaction is required; successful probing reveals only whether a supplied email address has an account.
The record
- CVE
- CVE-2026-25222
- Published
- Feb 2, 2026
- Updated
- Feb 2, 2026
- Vendor
- PolarNL
- Product
- PolarLearn
- Classifications
- CWE-200, T1087
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 2, 2026CVE publishedPublication date reported by the CVE source.
- Feb 2, 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=<= 0-PRERELEASE-15
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
- PolarLearn sign-in timing proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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