---
id: CVE-2026-54617
title: GravitLauncher is an open-source Minecraft launcher based on sashok724's v3
summary: >-
  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…
severity: critical
cvss: 9.8
cvssVector: '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
vendor: GravitLauncher
product: Launcher
affected:
  - Launcher < 5.7.12
published: '2026-09-17'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:25:27.050'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-54617'
references:
  - url: >-
      https://github.com/GravitLauncher/Launcher/commit/8114a1d4cfbcaab4c1c337d921597805d71dee3b
    label: security-advisories@github.com
  - url: 'https://github.com/GravitLauncher/Launcher/releases/tag/v5.7.12'
    label: security-advisories@github.com
  - url: >-
      https://github.com/GravitLauncher/Launcher/security/advisories/GHSA-5g75-477j-2c2f
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-5g75-477j-2c2f'
tags:
  - nvd
  - cve.org
  - ghsa
  - maven
epss: 0.00677
epssPercentile: 0.50216
ecosystem: maven
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-18T17:32:35.745645Z'
ingestedAt: '2026-07-02T21:44:45.091Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-54617)

Affected packages:

- `pro.gravit.launcher:launchserver-api <= 5.7.11`

Source: https://github.com/advisories/GHSA-5g75-477j-2c2f