# CVE-2026-25221: PolarLearn has Multiple Login CSRFs via Missing OAuth state Parameter (GitHub & Google)

> Attackers can force victims to log into attacker-controlled accounts via missing OAuth state validation, causing data loss and information disclosure.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 2 Feb 2026
- **Updated:** 3 Feb 2026
- **Also known as:** GHSA-fhhm-574m-7rpw

## What is CVE-2026-25221?

CVE-2026-25221 is a low-severity vulnerability in polarnl PolarLearn, published on 2 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

PolarLearn is a free and open-source learning program. In 0-PRERELEASE-15 and earlier, the OAuth 2.0 implementation for GitHub and Google login providers is vulnerable to Login Cross-Site Request Forgery (CSRF). The application fails to implement and verify the state parameter during the authentication flow. This allows an attacker to pre-authenticate a session and trick a victim into logging into the attacker's account. Any data the victim then enters or academic progress they make is stored on the attacker's account, leading to data loss for the victim and information disclosure to the attacker.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-25221?

It affects 1 product.


Products: Polarlearn Polarlearn.

## How do I fix CVE-2026-25221?

No fix has been published for CVE-2026-25221 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-25221 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25221 exists.

## Other vulnerabilities in polarnl PolarLearn

- [CVE-2026-25885](https://insights.sbomify.com/CVE-2026-25885/): PolarLearn allows Unauthenticated WebSocket access allows subscribing to and posting in arbitrary group chats (critical 10.0)
- [CVE-2026-39322](https://insights.sbomify.com/CVE-2026-39322/): PolarLearn: Any password authenticates banned accounts and grants API access (critical 9.2)
- [CVE-2026-35610](https://insights.sbomify.com/CVE-2026-35610/): PolarLearn has a Server Action Admin Bypass in Account Management Actions (high 8.8)
- [CVE-2026-25126](https://insights.sbomify.com/CVE-2026-25126/): PolarLearn's unvalidated vote direction allows vote count manipulation (high 7.1)
- [CVE-2026-25222](https://insights.sbomify.com/CVE-2026-25222/): PolarLearn Affected by User Enumeration via Argon2 Timing Attack on Sign-In Endpoint (medium 6.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25221 and fix it if it is affected.

What it is: CVE-2026-25221 is a low-severity vulnerability in polarnl PolarLearn, published on 2 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-25221 exists.

Affected product: polarnl PolarLearn. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-25221/ (Markdown: https://insights.sbomify.com/CVE-2026-25221/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25221
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25221
- OSV: https://osv.dev/vulnerability/CVE-2026-25221

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25221/
Summaries are generated and may contain mistakes; the official description above is the record.