Review reviewCritical

CVE-2026-33746

ConvoyPanel panel, convoy

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 a...

CVSS: 9.8
EPSS: 0.30%
CISA KEV: Not listed
Published: 2026.04.03

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.30%

Technical severityCVSS 9.8

Vulnerability overview

Affected product and versions

Product: ConvoyPanel panel, convoy
Affected versions: >= >= 3.9.0-beta, < 4.5.1
Fixed versions: 4.5.1

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that ConvoyPanel panel, convoy and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-287, CWE-347