CVE-2026-25126 PolarLearn's unvalidated vote direction allows vote count manipulation
Attackers can manipulate vote counts by sending invalid direction values, bypassing intended business logic in PolarLearn.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25126?
CVE-2026-25126 is a high-severity vulnerability in polarnl PolarLearn, published on 29 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-20
Which versions are affected by CVE-2026-25126?
It affects 1 product.
Products include Polarlearn Polarlearn.
How do I fix CVE-2026-25126?
No fix has been published for CVE-2026-25126 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25126 being exploited?
There is no known exploitation of CVE-2026-25126 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in polarnl PolarLearn
- CVE-2026-25885 PolarLearn allows Unauthenticated WebSocket access allows subscribing to and posting in arbitrary group chats
- CVE-2026-39322 PolarLearn: Any password authenticates banned accounts and grants API access
- CVE-2026-35610 PolarLearn has a Server Action Admin Bypass in Account Management Actions
- CVE-2026-25222 PolarLearn Affected by User Enumeration via Argon2 Timing Attack on Sign-In Endpoint
- CVE-2026-25221 PolarLearn has Multiple Login CSRFs via Missing OAuth state Parameter (GitHub & Google)
Sources
Also known as GHSA-ghpx-5w2p-p3qp.