CVE-2026-25726 Cloudreve is vulnerable to Account Takeover via Weak Cryptographic Token Generation (Insecure PRNG Seeding)

What is CVE-2026-25726?

CVE-2026-25726 is a high-severity vulnerability in cloudreve, published on 3 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-338

Which versions are affected by CVE-2026-25726?

5 open source packages ship an affected version, including github.com/cloudreve/Cloudreve/v4, github.com/cloudreve/Cloudreve and github.com/cloudreve/Cloudreve/v3. It affects 1 product.

Products include Cloudreve Cloudreve.

How do I fix CVE-2026-25726?

Upgrade github.com/cloudreve/Cloudreve/v4 to 4.0.0-20260205113604-ec9fdd33bc54 or later.

Is CVE-2026-25726 being exploited?

There is no known exploitation of CVE-2026-25726 in the wild and no public exploit code.

Other vulnerabilities in cloudreve

• CVE-2022-32167 Cloudreve - Stored XSS Medium 5.4

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-f8xp-wvcx-p6f4, GO-2026-5350.