Quick answers
- Is CVE-2026-111056 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-111056 being exploited in the wild.
- How severe is CVE-2026-111056?
- Informational severity, published 19 October 2026.
- Which products and versions are affected?
- FOSSBilling 0.1.0 to 0.8.6.
- Is there a fix for CVE-2026-111056?
- Yes: fixed in 0.8.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-111056 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-111056?
- 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.
How to fix
- Fixed in: 0.8.7
Technical details
The POST /api/guest/client/create endpoint exposed an email enumeration vulnerability: the Guest::create() method threw a distinct "already registered" exception when an email belonged to an existing client, versus returning a new client ID for new registrations. Unauthenticated attackers could exploit this by comparing API responses to determine which email addresses are registered. The fix changes the endpoint to silently skip account creation for existing emails and fall through to a login attempt, eliminating the discernible error response.
Affected products
- FOSSBilling FOSSBilling 0.1.0 to 0.8.6
Timeline
- 2026-10-19: disclosed
- 2026-08-28: patched