VulnerabilityAnalyzed

CVE-2026-25885

PolarLearn is a free and open-source learning program.

CRITICAL 10.0EPSS 0.30%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 10.0 CRITICALCVSS: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/M
EPSS: 0.30% probability · 22th percentile
CISA KEV: Not listed
Weakness: CWE-285, CWE-306
Affected: polarlearn/polarlearn
Source: security-advisories@github.com

References

https://github.com/polarnl/PolarLearn/commit/3ba588fda0d3f8e238483a20772719f27e52e79fPatch
https://github.com/polarnl/PolarLearn/security/advisories/GHSA-gvjm-5pw7-6c8cExploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.