CVE-2021-39177
7.4 HIGHGeyser is a bridge between Minecraft: Bedrock Edition and Minecraft: Java Edition
Published: 2021-08-30 · Last updated: 2026-06-17
Severity and scoring
- CVSS
- 7.4 HIGH
- Vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
- CWE
- CWE-287
Affected products
| Vendor | Product |
|---|---|
| geysermc | geyser |
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.
Source: NVD
References
- [NVD]https://nvd.nist.gov/vuln/detail/CVE-2021-39177
- [Patch]https://github.com/GeyserMC/Geyser/commit/b9541505af68ac7b7c093206ac7b1ba88957a5a6
- [Patch]https://github.com/GeyserMC/Geyser/security/advisories/GHSA-h77f-xxx7-4858
- [Other]https://updates.playhive.com/weekend-maintenance-disclosure-2kJMaY
- [Patch]https://github.com/GeyserMC/Geyser/commit/b9541505af68ac7b7c093206ac7b1ba88957a5a6
- [Patch]https://github.com/GeyserMC/Geyser/security/advisories/GHSA-h77f-xxx7-4858
- [Other]https://updates.playhive.com/weekend-maintenance-disclosure-2kJMaY
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