How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

361,925

Total vulnerabilities in the database

CVE-2026-54617 — pro.gravit.launcher / launchserver-api

Exposure of Sensitive Information to an Unauthorized Actor

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/ecdsa_id), 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:

path = Paths.get(IOHelper.getPathFromUrlFragment(uri)).normalize().toString().substring(1); // line 194
File file = base.resolve(path).toFile();                                                     // line 200 - no second normalize()

substring(1) blindly strips a leading slash, assuming the request-target always starts with /. Netty's HttpServerCodec accepts a request-target without a leading slash verbatim (decoderResult().isSuccess() == true). For such a target, normalize() cannot collapse the leading .., substring(1) turns ../ into ./ (leaving the remaining ..), and base.resolve(path), which is not re-normalized, resolves outside updatesDir.

file.isHidden() (line 201) is checked only on the final path component, so targets that don't start with a dot (ecdsa_id, rsa_id, legacySalt, LaunchServer.json) are served even with showHiddenFiles=false.

The file server is enabled by default (netty.fileServerEnabled=true) and bound to 0.0.0.0:9274. No auth handler precedes FileServerHandler; WebSocketServerProtocolHandler("/api") forwards non-WebSocket / non-/api requests down to it, so the attack is a plain HTTP GET (no WebSocket).

PoC

Reproduced on a from-source build of v5.7.11 (Netty 4.2.12). Must use a raw socket. curl/browsers/HTTP libraries normalize the path and prepend /, hitting the safe branch (false "not reproducible").

printf &#039;GET ../../.keys/ecdsa_id HTTP/1.1\r\nHost: x\r\n\r\n&#039; | nc &lt;host&gt; 9274

Returns the raw ECDSA private-key bytes. Same for ../../.keys/rsa_id, ../../.keys/legacySalt, ../../LaunchServer.json. %2e%2e/... (no leading slash) also works. Depth-robust arbitrary read: ../../../../../../etc/passwd. Control (confirms the root cause): GET /../../.keys/ecdsa_id (WITH leading slash) → 404. Only the no-leading-slash form escapes.

Impact

Unauthenticated remote read of any file the process can access. What that exposes:

.keys/ecdsa_id: the key that signs access JWTs. With it, an attacker mints a valid token for any account, including admins, so this is a full authentication bypass.
.keys/legacySalt: lets an attacker forge refresh tokens.
LaunchServer.json: database credentials.
Any other file readable by the process (config, logs, system files).

Deployment note: a normalizing L7 reverse proxy (stock nginx location / { proxy_pass ...; }) rejects the no-leading-slash request (400) and collapses leading-slash traversal, blocking the primary vector. But the default bind is 0.0.0.0:9274, so protection relies on firewalling the backend port; L4/TCP proxies (HAProxy TCP, nginx stream, CF Spectrum) and direct exposure remain exploitable.

Suggested fix

Re-normalize() after base.resolve(path) and verify resolved.startsWith(base).
Reject request-targets that don't start with / (400).
Default-bind to 127.0.0.1; store .keys outside updatesDir.

Published: Jul 2, 2026
Updated: Jul 3, 2026
CVE: CVE-2026-54617
GHSA: GHSA-5g75-477j-2c2f
Severity: Critical
Exploit:
CISA KEV:

CVSS v3:

Severity: Critical
Score: 9.8
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWEs:

OWASP TOP 10:

Affected Software
References

Software	From	Fixed in
pro.gravit.launcher / launchserver-api	-	5.7.11.x

https://github.com/GravitLauncher/Launcher/security/advisories/GHSA-5g75-477j-2c2f

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.