Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:N) | No attack requirements |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:H) | High integrity impact |
| Availability (VA:L) | Low availability impact |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
About Polarlearn
CVE-2026-25885 affects Polarlearn, a product from Polarlearn. Before acting, confirm where Polarlearn runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: 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.
The weakness class is Improper Authorization. The software does not check whether a user is allowed to perform an action.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Polarlearn |
| Affected versions | Polarlearn all listed versions |
| Published | Feb 9, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Polarlearn and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Polarlearn named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Polarlearn to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-285: Improper Authorization More CVEs with this weakness
- CWE-306: Missing Authentication More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
PolarLearn is a free and open-source learning program. In 0-PRERELEASE-15 and earlier, POST /api/v1/auth/sign-in creates a valid session for banned accounts before verifying the supplied password. That session is then accepted across authenticated /api routes, enabling account data access and authenticated actions as the banned user.
In addInputMethodListener of com.android.server.inputmethod.InputMethodManagerService, there is a missing permission check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
Improper limitation of a pathname to a restricted directory ('path traversal') in Azure Logic Apps allows an unauthorized attacker to elevate privileges over a network.
Improper authorization in Azure AI Foundry allows an unauthorized attacker to elevate privileges over a network.
Improper authorization in Microsoft Azure Kubernetes Service allows an unauthorized attacker to elevate privileges over a network.
FUXA is a web-based Process Visualization (SCADA/HMI/Dashboard) software. Prior to 1.2.10, an authentication bypass vulnerability in FUXA allows an unauthenticated, remote attacker to gain administrative access via the heartbeat refresh API and execute arbitrary code on the server. This issue has been patched in FUXA version 1.2.10.
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