Vulnerability Description
Convoy is a KVM server management panel for hosting businesses. From version 3.9.0-beta to before version 4.5.1, the JWTService::decode() method did not verify the cryptographic signature of JWT tokens. While the method configured a symmetric HMAC-SHA256 signer via lcobucci/jwt, it only validated time-based claims (exp, nbf, iat) using the StrictValidAt constraint. The SignedWith constraint was not included in the validation step. This means an attacker could forge or tamper with JWT token payloads — such as modifying the user_uuid claim — and the token would be accepted as valid, as long as the time-based claims were satisfied. This directly impacts the SSO authentication flow (LoginController::authorizeToken), allowing an attacker to authenticate as any user by crafting a token with an arbitrary user_uuid. This issue has been patched in version 4.5.1.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Convoypanel | Convoy | < 4.5.1 |
Related Weaknesses (CWE)
References
- https://github.com/ConvoyPanel/panel/releases/tag/v4.5.1Release Notes
- https://github.com/ConvoyPanel/panel/security/advisories/GHSA-92pg-3w49-4w5xVendor Advisory
FAQ
What is CVE-2026-33746?
CVE-2026-33746 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Convoy is a KVM server management panel for hosting businesses. From version 3.9.0-beta to before version 4.5.1, the JWTService::decode() method did not verify the cryptographic signature of JWT token...
How severe is CVE-2026-33746?
CVE-2026-33746 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-33746?
Check the references section above for vendor advisories and patch information. Affected products include: Convoypanel Convoy.