Vulnerability · Published Jun 2, 2026 · Assigned by GitHub_M

CVE-2026-45289CloudburstMC Protocol: Partially missing validation for FULL type authentication tokens

Medium 5.3

In plain English

A medium-severity improper authentication in Protocol from CloudburstMC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.1%top 96.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
CloudburstMC	Protocol	< 3.0.0.Beta12-20260420.182526-15

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

https://github.com/CloudburstMC/Protocol/security/advisories/GHSA-g2fr-c75x-4hf9 x_refsource_CONFIRM