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TI-2026-20372 Aliases CVE-2026-25222

PolarLearn Affected by User Enumeration via Argon2 Timing Attack on Sign-In Endpoint

Priority MEDIUM 61CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-200.

Summary

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).

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00458 39th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
polarnlPolarLearnup to 0-PRERELEASE-15—No fix listedCNA
  • PolarLearn Vendorpolarnl Affected up to 0-PRERELEASE-15 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:polarlearn:polarlearn:-:*:*:*:*:*:*:*not specified by NVDVulnerablepolarnl
  • cpe:2.3:a:polarlearn:polarlearn:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·polarnl

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-25222

References

Exploit 1

Patch 1

  • TI-2026-27712 PolarLearn has a Server Action Admin Bypass in Account Management Actions CVSS 3.1HIGH 8.8
  • TI-2026-20925 PolarLearn allows Unauthenticated WebSocket access allows subscribing to and posting in arbitrary group chats CVSS 4.0CRITICAL 10.0
  • TI-2026-20371 PolarLearn has Multiple Login CSRFs via Missing OAuth state Parameter (GitHub & Google) CVSS 4.0LOW 2.3
  • TI-2026-28311 PolarLearn: Any password authenticates banned accounts and grants API access CVSS 4.0CRITICAL 9.2
  • TI-2026-20289 PolarLearn's unvalidated vote direction allows vote count manipulation CVSS 3.1HIGH 7.1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences