Quick answers
- Is CVE-2026-42341 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-42341 being exploited in the wild.
- How severe is CVE-2026-42341?
- Informational severity, with a CVSS score of 9.2, published 6 July 2026.
- Which products and versions are affected?
- FOSSBilling >= 0.6.0, <= 0.7.2.
- Is there a fix for CVE-2026-42341?
- A patch was published on 2026-08-01: Fixed in version 0.8.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-42341 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-42341?
- Check whether you run FOSSBilling at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
An unauthenticated payment bypass exists in FOSSBilling's Instant Payment Notification (IPN) callback endpoint (`ipn.php`). The vulnerability is caused by three primary failures: the `ipn.php` script hardcodes a flag to skip validation of invoice IDs, the processing logic bypasses the standard `isIpnValid()` security checks, and the 'Custom' payment adapter lacks any source or signature verification. An attacker can exploit this by sending a crafted HTTP request to the IPN endpoint to credit client accounts or activate orders. Because invoice IDs are sequential, an attacker could potentially automate the exploitation of multiple invoices. The issue is resolved in version 0.8.0.
Affected products
- FOSSBilling FOSSBilling >= 0.6.0, <= 0.7.2
Timeline
- 2026-06-20: advisory: GitHub Security Advisory published
- 2026-07-06: disclosed: NVD publication date
- 2026-08-01: patched: Fixed in version 0.8.0