CVE-2026-42341
criticalpriority · track · 0OT risk · elevatedEPSS 0.003 · 20 %ileEUEPSS · scored 2026-10-28
FOSSBilling is a free, open-source billing and client management system. Versions 0.6.0 through 0.7.2 have an unauthenticated payment bypass vulnerability in FOSSBilling's IPN callback endpoint. When the Custom payment adapter is enabled, an attacker can mark any unpaid invoice as paid and credit the associated client account without making an actual payment, by sending a single crafted HTTP request. Version 0.8.0 patches the issue. Some workarounds are available. Disable the Custom payment gateway if not actively needed and/or restrict access to `/ipn.php` at the web server level (e.g., via IP allowlisting), noting that this may interfere with legitimate payment callback processing.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.7–9.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
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affected products (1)
Products and version ranges known to be affected.
also known as (2)
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sources
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references (3)
External citations — patches, advisories, analysis.
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