What’s Vulnerable › Vulnerabilities
CVE-2026-53642: FOSSBilling: Unverified clients can access client-area pages when email confirmation is required
- Severity: medium (CVSS 5.3 v4.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-07-06 · updated 2026-07-07
- Weakness: CWE-863
Description
FOSSBilling is a free, open-source billing and client management system. In versions 0.5.6 through 0.7.2, when the "Require Email Confirmation" setting is enabled, a logged-in client with an unverified email address (`email_approved = 0`) can access all client-area pages (e.g. `/client/balance`, `/client/order/list`, `/client/invoice`) and read real account data, including wallet balances and transaction history. The API-side enforcement correctly restricts unverified clients to only profile-related endpoints, but the page-side enforcement is overly permissive, allowing any request whose path starts with `/client`. Version 0.8.0 contains a fix. No known workarounds that don't involve modifying the source code are available.
Affected products
- FOSSBilling: from 0.5.6, < 0.8.0
References
Get alerted when CVE-2026-53642 or the next vulnerability affects your stack