CVE-2026-33746 Convoy: JWT Signature Verification Bypass Allows Authentication as Arbitrary Users
Attackers can bypass JWT signature verification to forge tokens and authenticate as any user in the Convoy KVM management panel.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33746?
CVE-2026-33746 is a critical authentication bypass vulnerability in ConvoyPanel panel, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-33746?
It affects 1 product.
Products include Convoypanel Convoy.
How do I fix CVE-2026-33746?
No fix has been published for CVE-2026-33746 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-33746 being exploited?
There is no known exploitation of CVE-2026-33746 in the wild and no public exploit code.
Sources
Also known as GHSA-92pg-3w49-4w5x.