Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cloudreve | Cloudreve | < 4.13.0 |
Related Weaknesses (CWE)
References
- https://github.com/cloudreve/cloudreve/releases/tag/4.13.0ProductRelease Notes
- https://github.com/cloudreve/cloudreve/security/advisories/GHSA-f8xp-wvcx-p6f4MitigationVendor Advisory
FAQ
What is CVE-2026-25726?
CVE-2026-25726 is a vulnerability with a CVSS score of 8.1 (HIGH). 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 gene...
How severe is CVE-2026-25726?
CVE-2026-25726 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-25726?
Check the references section above for vendor advisories and patch information. Affected products include: Cloudreve Cloudreve.