# CVE-2026-25885: PolarLearn allows Unauthenticated WebSocket access allows subscribing to and posting in arbitrary group chats

> Unauthenticated users can subscribe to and post messages in any group chat, allowing unauthorized access to private conversations and data modification.

- **Severity:** Critical 10.0 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Feb 2026
- **Updated:** 10 Feb 2026
- **Also known as:** GHSA-gvjm-5pw7-6c8c

## What is CVE-2026-25885?

CVE-2026-25885 is a critical missing authorization vulnerability in polarnl PolarLearn, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

PolarLearn is a free and open-source learning program. In 0-PRERELEASE-16 and earlier, the group chat WebSocket at wss://polarlearn.nl/api/v1/ws can be used without logging in. An unauthenticated client can subscribe to any group chat by providing a group UUID, and can also send messages to any group. The server accepts the message and stores it in the group’s chatContent, so this is not just a visual spam issue.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-25885?

It affects 1 product.


Products: Polarlearn Polarlearn.

## How do I fix CVE-2026-25885?

No fix has been published for CVE-2026-25885 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-25885 being exploited?

There is no known exploitation of CVE-2026-25885 in the wild and no public exploit code.

## Other vulnerabilities in polarnl PolarLearn

- [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)
- [CVE-2026-25221](https://insights.sbomify.com/CVE-2026-25221/): PolarLearn has Multiple Login CSRFs via Missing OAuth state Parameter (GitHub & Google) (low 2.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-25885 and fix it if it is affected.

What it is: CVE-2026-25885 is a critical missing authorization vulnerability in polarnl PolarLearn, published on 9 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-25885 in the wild and no public exploit code.

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-2026-25885/ (Markdown: https://insights.sbomify.com/CVE-2026-25885/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25885
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25885
- OSV: https://osv.dev/vulnerability/CVE-2026-25885

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-25885/
Summaries are generated and may contain mistakes; the official description above is the record.