CVE-2026-25222
PolarLearn Affected by User Enumeration via Argon2 Timing Attack on Sign-In Endpoint
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).
INFO
Published Date :
Feb. 2, 2026, 11:16 p.m.
Last Modified :
Feb. 2, 2026, 11:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-25222
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Always perform password hashing, regardless of user existence.
- Introduce a small, random delay to responses.
- Consider using constant-time comparison for security checks.
- Update PolarLearn to a version without this vulnerability.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-25222.
| URL | Resource |
|---|---|
| https://github.com/polarnl/PolarLearn/commit/6c276855172c7310cce0df996cb47ffe0d886741 | |
| https://github.com/polarnl/PolarLearn/security/advisories/GHSA-wcr9-mvr9-4qh5 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-25222 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-25222
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-25222 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-25222 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Feb. 02, 2026
Action Type Old Value New Value Added 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). Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-200 Added Reference https://github.com/polarnl/PolarLearn/commit/6c276855172c7310cce0df996cb47ffe0d886741 Added Reference https://github.com/polarnl/PolarLearn/security/advisories/GHSA-wcr9-mvr9-4qh5