LaunchServer FileServerHandler has an unauthenticated path traversal issue

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-54617: 3.46% estimated exploitation activity in the next 30 days; percentile 89.05 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary An unauthenticated path traversal in the LaunchServer HTTP file server (FileServerHandler) lets any remote actor read any file readable by the LaunchServer process (e.g. ../../../../etc/passwd). This is a generic arbitrary-file-read primitive, so the fix must address the traversal itself, not any specific file. The readable files include the server's own secrets, which turns this from information disclosure into full compromise: the ECDSA private key that signs access JWTs (.keys/ecdsaid), the refresh-token salt (.keys/legacySalt), and LaunchServer.json (database credentials). With the signing key an attacker mints a valid access token for any account, including admins. That is a full authentication bypass. Pre-auth, default config, port 9274. Affected: GravitLauncher LaunchServer ≤ 5.7.11 (the LaunchServer application; the published pro.gravit.launcher:-api Maven artifacts do not contain the vulnerable code). Details In FileServerHandler.channelRead0: substring(1) blindly…

Published by the source

2 Jul 2026, 20:49 UTC

Last modified by the source

2 Jul 2026, 20:49 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5g75-477j-2c2f

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# Patch Next advisory brief: CVE-2026-54617

Advisory: LaunchServer FileServerHandler has an unauthenticated path traversal issue
IDs: CVE-2026-54617, GHSA-5g75-477j-2c2f
Record: https://patchnext.com/advisories/cve-2026-54617 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven pro.gravit.launcher:launchserver-api: affected <= 5.7.11

## Suggested inspection (read-only)
- Maven pro.gravit.launcher:launchserver-api: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pro.gravit.launcher:launchserver-api.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5g75-477j-2c2f (GitHub-reviewed advisory GHSA-5g75-477j-2c2f lists affected ranges: Maven pro.gravit.launcher:launchserver-api >=0 <=5.7.11)

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