What is CVE-2026-25885?

CVE-2026-25885 is a high-severity vulnerability in Polarlearn, classified under Improper Authorization. CVSS score: 7.5/10. Published 2026-02-09.

How severe is CVE-2026-25885?

High severity. CVSS v3 base score is 7.5 out of 10.

Auth bypass in Polarlearn

CVE-2026-25885

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.

Published 2026-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (34.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Polarlearn
Polarnl Polarlearn — versions < 0-PRERELEASE-16

Weakness classification (CWE)

References

github.com/polarnl/PolarLearn/security/advisories/GHSA-gvjm-5pw7-6c8c (Exploit, Vendor Advisory)
github.com/polarnl/PolarLearn/commit/3ba588fda0d3f8e238483a20772719f27e52e79f (Patch)

Frequently asked questions

What is CVE-2026-25885?: CVE-2026-25885 is a high-severity vulnerability in Polarlearn, classified under Improper Authorization. CVSS score: 7.5/10. Published 2026-02-09.
How severe is CVE-2026-25885?: High severity. CVSS v3 base score is 7.5 out of 10.