Vulnerability in Flarum Framework

CVE-2025-27794

Flarum is open-source forum software. A session hijacking vulnerability exists in versions prior to 1.8.10 when an attacker-controlled authoritative subdomain under a parent domain (e.g., `subdomain.host.com`) sets cookies scoped to the pa…

EPSS: 0.004 (59.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-27794?
CVE-2025-27794 is a medium-severity vulnerability in Flarum Framework, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 6.8/10. Published 2025-03-12.
How severe is CVE-2025-27794?
Medium severity. CVSS v3 base score is 6.8 out of 10.
Is CVE-2025-27794 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.