Vulnerability · Published Feb 2, 2026 · Assigned by GitHub_M
CVE-2026-25222PolarLearn Affected by User Enumeration via Argon2 Timing Attack on Sign-In Endpoint
Medium 6.3
In plain English
A medium-severity information exposure in PolarLearn from polarnl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Official description
PolarLearn is a free and open-source learning program. In 0-PRERELEASE-15 and earlier, a timing attack vulnerability in the sign-in process allows unauthenticated attackers to determine if a specific email address is registered on the platform. By measuring the response time of the login endpoint, an attacker can distinguish between valid and invalid email addresses. This occurs because the server only performs the computationally expensive Argon2 password hashing if the user exists in the database. Requests for existing users take significantly longer (~650ms) than requests for non-existent users (~160ms).
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| polarnl | PolarLearn | <= 0-PRERELEASE-15 |
Weakness: CWE-200 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N