polarnl PolarLearn prior 0-PRERELEASE-15 Vote API /api/v1/forum/vote votes_data direction input validation

Summaryinfo

A vulnerability identified as critical has been detected in polarnl PolarLearn. This impacts the function votes_data of the file /api/v1/forum/vote of the component Vote API. This manipulation of the argument direction causes input validation. The identification of this vulnerability is CVE-2026-25126. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in polarnl PolarLearn. It has been declared as critical. Affected by this vulnerability is the function votes_data of the file /api/v1/forum/vote of the component Vote API. The manipulation of the argument direction with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-25126 since 01/29/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available.

Upgrading to version 0-PRERELEASE-15 eliminates this vulnerability. Applying the patch e6227d94d0e53e854f6a46480db8cd1051184d41 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-4937). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• polarnl

Name

• PolarLearn

License

• open-source

Website

• Product: https://github.com/polarnl/PolarLearn/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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