Auth bypass in Mythicalltd Featherpanel
CVE-2026-84715
FeatherPanel versions before 1.3.7.10 fail to validate permissions in the SubuserController updateSubuser handler, allowing authenticated subusers to modify their own permission records. A subuser with minimal permissions can send a crafted request to grant themselves full server control, enabling unauthorized access to sensitive data, backups, and server configuration.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (45.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 45.7% 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: 0.006 · change: +0.002
Affected products
Weakness classification (CWE)
References
- Patch Commit (patch)
- FeatherPanel v1.3.7.10 Release Notes (release-notes)
- github.com/MythicalLTD/FeatherPanel/blob/376b003aa9685b74153d239d2b3f64a752cdc0… (technical-description)
- github.com/MythicalLTD/FeatherPanel/blob/376b003aa9685b74153d239d2b3f64a752cdc0… (technical-description)
- github.com/MythicalLTD/FeatherPanel (product)
- VulnCheck Advisory: FeatherPanel before 1.3.7.10 Privilege Escalation via Subuser Permission Update (third-party-advisory)
Frequently asked questions
- What is CVE-2026-84715?
- CVE-2026-84715 is a high-severity vulnerability in Mythicalltd Featherpanel, classified under Missing Authorization. CVSS score: 8.8/10. Published 2026-09-02.
- How severe is CVE-2026-84715?
- High severity. CVSS v3 base score is 8.8 out of 10.