CVE-2026-25126 HIGH

CVE-2026-25126: PolarLearn's unvalidated vote direction allows vote count manipulation

Vendor Polarnl
Product PolarLearn
Weakness CWE-20 · Input validation
Published January 29, 2026
Last update February 2, 2026
View on NVD All CVEs

CVSS base score

7.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

What the vulnerability does

01Description

PolarLearn is a free and open-source learning program. Prior to version 0-PRERELEASE-15, the vote API route (`POST /api/v1/forum/vote`) trusts the JSON body’s `direction` value without runtime validation. TypeScript types are not enforced at runtime, so an attacker can send arbitrary strings (e.g., `"x"`) as `direction`. Downstream (`VoteServer`) treats any non-`"up"` and non-`null` value as a downvote and persists the invalid value in `votes_data`. This can be exploited to bypass intended business logic. Version 0-PRERELEASE-15 fixes the vulnerability.

Key dates

02Disclosure timeline

January 29, 2026 CVE published
February 2, 2026 Record updated