CVE-2026-25726
Cloudreve is vulnerable to Account Takeover via Weak Cryptographic Token Generation (Insecure PRNG Seeding)
Description
Cloudreve is a self-hosted file management and sharing system. Prior to version 4.13.0, the application uses the weak pseudo-random number generator math/rand seeded with time.Now().UnixNano() to generate critical security secrets, including the secret_key, and hash_id_salt. These secrets are generated upon first startup and persisted in the database. An attacker can exploit this by obtaining the administrator's account creation time (via public API endpoints) to narrow the search window for the PRNG seed, and use known hashid to validate the seed. By brute-forcing the seed (demonstrated to take <3 hours on general consumer PC), an attacker can predict the secret_key. This allows them to forge valid JSON Web Tokens (JWTs) for any user, including administrators, leading to full account takeover and privilege escalation. This issue has been patched in version 4.13.0.
INFO
Published Date :
April 3, 2026, 8:16 p.m.
Last Modified :
July 24, 2026, 10:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update Cloudreve to version 4.13.0.
- Generate new security secrets after updating.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-25726.
| URL | Resource |
|---|---|
| https://github.com/cloudreve/cloudreve/releases/tag/4.13.0 | Product Release Notes |
| https://github.com/cloudreve/cloudreve/security/advisories/GHSA-f8xp-wvcx-p6f4 | Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-25726 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-25726
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-25726 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-25726 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Jul. 24, 2026
Action Type Old Value New Value Added Translation Title: cloudreve, Description: Cloudreve es un sistema de gestión y compartición de archivos autoalojado. Antes de la versión 4.13.0, la aplicación utiliza el generador de números pseudoaleatorios débil math/rand inicializado con time.Now().UnixNano() para generar secretos de seguridad críticos, incluyendo la secret_key y el hash_id_salt. Estos secretos se generan en el primer inicio y se persisten en la base de datos. Un atacante puede explotar esto obteniendo el tiempo de creación de la cuenta del administrador (a través de puntos finales de la API públicos) para reducir la ventana de búsqueda para la semilla del PRNG, y usar un hashid conocido para validar la semilla. Mediante fuerza bruta sobre la semilla (demostrado que toma <3 horas en una PC de consumidor general), un atacante puede predecir la secret_key. Esto les permite falsificar JSON Web Tokens (JWTs) válidos para cualquier usuario, incluidos los administradores, lo que lleva a una toma de control total de la cuenta y escalada de privilegios. Este problema ha sido parcheado en la versión 4.13.0. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'cloudreve', 'product': 'cloudreve', 'versions': [{'status': 'affected', 'version': '< 4.13.0'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-25726', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-04-04T03:21:10.510009Z'} -
Initial Analysis by [email protected]
Apr. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:cloudreve:cloudreve:*:*:*:*:*:*:*:* versions up to (excluding) 4.13.0 Added Reference Type GitHub, Inc.: https://github.com/cloudreve/cloudreve/releases/tag/4.13.0 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/cloudreve/cloudreve/security/advisories/GHSA-f8xp-wvcx-p6f4 Types: Mitigation, Vendor Advisory -
New CVE Received by [email protected]
Apr. 03, 2026
Action Type Old Value New Value Added Description Cloudreve is a self-hosted file management and sharing system. Prior to version 4.13.0, the application uses the weak pseudo-random number generator math/rand seeded with time.Now().UnixNano() to generate critical security secrets, including the secret_key, and hash_id_salt. These secrets are generated upon first startup and persisted in the database. An attacker can exploit this by obtaining the administrator's account creation time (via public API endpoints) to narrow the search window for the PRNG seed, and use known hashid to validate the seed. By brute-forcing the seed (demonstrated to take <3 hours on general consumer PC), an attacker can predict the secret_key. This allows them to forge valid JSON Web Tokens (JWTs) for any user, including administrators, leading to full account takeover and privilege escalation. This issue has been patched in version 4.13.0. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-338 Added Reference https://github.com/cloudreve/cloudreve/releases/tag/4.13.0 Added Reference https://github.com/cloudreve/cloudreve/security/advisories/GHSA-f8xp-wvcx-p6f4