CVE-2026-33746: 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 n...

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.

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

0.30%

21.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Convoypanel	Convoy	< 4.5.1

References

https://github.com/ConvoyPanel/panel/releases/tag/v4.5.1Release Notes
https://github.com/ConvoyPanel/panel/security/advisories/GHSA-92pg-3w49-4w5xVendor Advisory

Timeline

Published: Apr 2, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33746?

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.

How severe is CVE-2026-33746?

CVE-2026-33746 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33746?

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.