CVE-2026-45289: Cloudburstmc Protocol

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

CloudburstMC Protocol is a protocol library for Minecraft Bedrock Edition. Prior to version 3.0.0.Beta12-20260420.182526-15, CloudburstMC Protocol is partially missing validation for FULL type authentication tokens (Cloudburst/Protocol). This vulnerability impacts publicly accessible software depending on the affected versions of Protocol, specifically the EncryptionUtils methods to validate auth payloads for FULL type tokens. This issue has been patched in version 3.0.0.Beta12-20260420.182526-15.

Affected products

• Cloudburstmc Protocol: before 3.0.0.Beta12-20260420.182526-15 (fixed in 3.0.0.Beta12-20260420.182526-15)

Published 2026-06-02. Last modified 2026-07-22.