CVE-2026-53646
FOSSBilling: Client password reset token reuse allows persistent account takeover
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.7
FOSSBilling: Client password reset token reuse allows persistent account takeover
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.
- Record
CVE-2026-53646- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-640
- Updated
- 2026-11-02
EUVDEUVD-2026-41971
7.7
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.
- Record
EUVD-2026-41971- CVSS 4.0
- 7.7 High
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 - Updated
- 2026-11-02
NVD
7.7
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.
- Record
CVE-2026-53646- CVSS 4.0
- 7.7 High
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-640
- Updated
- 2026-11-02
OSV
7.7
FOSSBilling: Client password reset token reuse allows persistent account takeover
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.
- Record
CVE-2026-53646- CVSS 4.0
- 7.7 High
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 - Weakness
- CWE-640
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53646 is a high vulnerability (CVSS 7.7) in Fossbilling, published July 6, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. No source names a fixed version.