---
cve: "CVE-2026-53646"
severity: "HIGH"
cvss: 7.7
epss: "22%"
vendor: "fossbilling"
kev: false
exploited: false
published: "2026-07-06 23:16:56"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-13T18:13:39+02:00"
---

# CVE-2026-53646

> 7.7 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Keine | bad |

## Patch verfügbar (OSV)

- 3bd35f5b2921d8a26a403142ae0408f95e6463cc (Commit)

## Referenzen

- <https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-vp66-w6rc-x32p>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53646) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_