VulnerabilityDeferred

CVE-2026-53643

Versions prior to 0.8.0 allow low-privileged staff accounts to perform unauthorized actions via admin API endpoints.

HIGH 8.7EPSS 0.35%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.35%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

FOSSBilling is a free, open-source billing and client management system. Versions prior to 0.8.0 allow low-privileged staff accounts to perform unauthorized actions via admin API endpoints. The root cause is a combination of the `can_always_access` module flag (which grants all staff access to certain modules) and insufficient permission checks or unsafe parameter handling on individual endpoints. Version 0.8.0 contains a fix. Some workarounds are available. Restrict staff accounts to only those who need access to sensitive settings and/or use a reverse proxy or WAF to restrict access to the affected endpoints to trusted IP addresses or higher-privilege roles.

CVSS 4.0: 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.35% probability · 28th percentile
CISA KEV: Not listed
Weakness: CWE-200, CWE-639, CWE-862
Source: security-advisories@github.com

References

https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-563q-g4r4-6f9m

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.