CVE-2026-53646

What it is

FOSSBilling is a free, open-source billing and client management system. In versions 0.5.6 through 0.7.2, when a `ClientPasswordReset` record already exists for a client (from a previous unexpired reset request), subsequent calls to the `reset_password` guest API endpoint reuse the existing token instead of generating a new one. The 15-minute validity window is anchored to the first request's `created_at` timestamp, not the time of the most recent email. An attacker who obtained the original reset link remains able to use it even after the victim requests a new reset, because the original token is never invalidated or rotated. Version 0.8.0 patches the issue. Some workarounds are available. Configure a reverse proxy (e.g., Nginx, Apache, Cloudflare) to apply per-IP rate limiting to the `/client/reset-password` endpoint to minimize the window of opportunity, and/or manually clear expired `client_password_reset` records from the database after a client reports a suspected compromise.

At a glance

Exploitability

Can be exploited over the network without logging in, but needs a user to act. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-06 23:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-07 15:16 UTC Last updatedMost recent change to the record

Details

Published

2026-07-06 23:16 UTC

Last modified

2026-07-07 15:16 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-640

Record status

Deferred

Attack profile CVSS 4.0 · 7.7

Attack vector

Network

Complexity

High

Attack requirements

Present

Privileges needed

None

User interaction

Passive

Confidentiality

High

Integrity

High

Availability

High