Critical 10.0Published Feb 9, 2026

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

Updated under an hour ago (Oct 27, 2026, 9:50 PM ET)

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It affects polarnl PolarLearn and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for polarnl PolarLearn

Exploited in the last 30 days

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.

CVSS: 10.0 CRITICAL (v4.0, CNA)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
Weakness (CWE): CWE-285, CWE-306
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Feb 10, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

polarnl PolarLearn polarnl:polarlearn (from the name)	before 0-PRERELEASE-16	CNA record
polarlearn polarlearn polarlearn:polarlearn	all versions	NVD

References

References

https://github.com/polarnl/PolarLearn/security/advisories/GHSA-gvjm-5pw7-6c8c	x-refsource-confirm, exploit, vendor-advisory
https://github.com/polarnl/PolarLearn/commit/3ba588fda0d3f8e238483a20772719f27e52e79f	x-refsource-misc, patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.