# CVE-2026-54617

## Summary

- **CVE ID:** CVE-2026-54617
- **Severity:** CRITICAL
- **CVSS Score:** 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** CWE-22, CWE-200, CWE-522
- **Published:** Sep 17, 2026
- **Last Modified:** Sep 17, 2026

## Description

GravitLauncher is an open-source Minecraft launcher based on sashok724's v3. Prior to 5.7.12, an unauthenticated remote actor can send a raw HTTP request target without a leading slash to the default LaunchServer file server on port 9274. FileServerHandler.channelRead0 in components/launchserver/src/main/java/pro/gravit/launchserver/socket/handlers/fileserver/FileServerHandler.java strips the first request-target character and resolves the remaining path against updatesDir without re-normalizing and verifying containment. This leaves parent-directory components in a no-leading-slash request and allows reading any file accessible to the LaunchServer process, including .keys/ecdsa_id, .keys/legacySalt, and LaunchServer.json. Disclosure of those files can expose signing keys, refresh-token material, and database credentials, enabling forged administrative access tokens and full authentication bypass. A normalizing L7 proxy may block the primary request form, but direct exposure and L4/TCP proxies remain affected, and netty.fileServerEnabled is enabled by default. This issue is fixed in 5.7.12.

## Affected Products

- GravitLauncher — Launcher (< 5.7.12)

## References

- [CNA](https://github.com/GravitLauncher/Launcher/security/advisories/GHSA-5g75-477j-2c2f)
- [CNA](https://github.com/GravitLauncher/Launcher/commit/8114a1d4cfbcaab4c1c337d921597805d71dee3b)
- [CNA](https://github.com/GravitLauncher/Launcher/releases/tag/v5.7.12)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.68%
- **EPSS Percentile:** 50.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-19._