VULNERABILITY INTELLIGENCE

CVE-2021-39177

CVSS score7.4 HIGH
EPSS probability1.44%
CISA KEVNot currently listed
Published2021-08-30
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Description

Geyser is a bridge between Minecraft: Bedrock Edition and Minecraft: Java Edition. Versions of Geyser prior to 1.4.2-SNAPSHOT allow anyone that can connect to the server to forge a LoginPacket with manipulated JWT token allowing impersonation as any user. Version 1.4.2-SNAPSHOT contains a patch for the issue. There are no known workarounds aside from upgrading.

Weakness classification

  • security-advisories@github.com: CWE-287

Primary references