Authentication Token Validation Flaw in Crucial Minecraft Protocol Library
CVE-2026-45289

5.3MEDIUM

Key Information:

Vendor

Cloudburstmc

Status
Protocol
Vendor
CVE Published:
2 June 2026

What is CVE-2026-45289?

A security flaw exists in the CloudburstMC Protocol prior to version 3.0.0.Beta12-20260420.182526-15, where there is inadequate validation of FULL type authentication tokens. This affects the software relying on the affected versions, especially in methods related to validating authentication payloads. Users should upgrade to the latest version to ensure security and protect against potential exploits.

Affected Version(s)

Protocol < 3.0.0.Beta12-20260420.182526-15

References

https://github.com/CloudburstMC/Protocol/security/advisor...
x_refsource_CONFIRM

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.