What’s Vulnerable › Vulnerabilities

CVE-2026-43918: Suspended or inactive FOSSBilling accounts can retain or regain access through existing sessions, API tokens, and password reset flows

• Severity: high (CVSS 8.7 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 2026-07-08
• Weakness: CWE-613

Description

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, when a client or staff/admin account is suspended or marked inactive, existing authenticated sessions are not invalidated. The session identity loaders in src/di.php (loggedin_client and loggedin_admin) only reject sessions if the backing account record no longer exists in the database. They do not verify that the account's status is still active. This allows a suspended or deactivated user to retain full access until their session naturally expires. This issue has been fixed in version 0.8.0.

Affected products

• FOSSBilling: before 0.8.0

References

• https://github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0
• https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-qv6c-v49w-8g2j

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