CVE-2025-62523: PILOS Misconfigured the Access-Control-Allow-Origin Header

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-27 · updated 2026-10-08
Weakness: CWE-942

Description

PILOS (Platform for Interactive Live-Online Seminars) is a frontend for BigBlueButton. PILOS before 4.8.0 includes a Cross-Origin Resource Sharing (CORS) misconfiguration in its middleware: it reflects the Origin request header back in the Access-Control-Allow-Origin response header without proper validation or a whitelist, while Access-Control-Allow-Credentials is set to true. This behavior could allow a malicious website on a different origin to send requests (including credentials) to the PILOS API. This may enable exfiltration or actions using the victim’s credentials if the server accepts those cross-origin requests as authenticated. Laravel’s session handling applies additional origin checks such that cross-origin requests are not authenticated by default. Because of these session-origin protections, and in the absence of any other unknown vulnerabilities that would bypass Laravel’s origin/session checks, this reflected-Origin CORS misconfiguration is not believed to be exploitable in typical PILOS deployments. This vulnerability has been patched in PILOS in v4.8.0

Affected products

THM-Health PILOS: before 4.8.0 — fixed in 4.8.0

How to fix

Upgrade to a fixed version: THM-Health PILOS 4.8.0. Check the vendor advisory for mitigations.

References

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