CVE-2026-25726

CRITICALCVSS 9.8/10EPSS 0.38%

Last modified

CVE-2026-25726 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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. EPSS estimates a 0.38% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.38%

29.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CloudreveCloudreve< 4.13.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-25726?
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.
How severe is CVE-2026-25726?
CVE-2026-25726 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.38% probability of exploitation in the next 30 days.
How do I fix CVE-2026-25726?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-25726?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST