Summary
Mockoon has a Path Traversal and LFI in the static file serving endpoint
A mock API configuration for static file serving following the same approach presented in the documentation page, where the server filename is generated via templating features from user input is vulnerable to Path Traversal and LFI, allowing an attacker to get any file in the mock server filesystem.
The issue may be particularly relevant in cloud hosted server instances
Details
In sendFileWithCallback(code) and sendFile(code) the filePath variable is parsed using TemplateParser
let filePath = TemplateParser({
shouldOmitDataHelper: false,
// replace backslashes with forward slashes, but not if followed by a dot (to allow helpers with paths containing properties with dots: e.g. {{queryParam 'path.prop\.with\.dots'}})
content: routeResponse.filePath.replace(/\\(?!\.)/g, '/'),
environment: this.environment,
processedDatabuckets: this.processedDatabuckets,
globalVariables: this.globalVariables,
request: serverRequest,
envVarsPrefix: this.options.envVarsPrefix
});
The path extracted from the request parameters used when composing the final file path is not sanitized and is vulnerable to path traversal exploits (e.g. ../../../../../etc/passwd)
PoC
Test setup
The issue has been tested with mockoon-cli, using the Docker image mockoon/cli:latest
# Folder setup
mkdir mockoon-test
cd mockoon-test
# put config.json in mockooon-test dir
mkdir static
# Run container
docker run -d --mount type=bind,source=./config.json,target=/data,readonly -v ./static:/static -p 3000:3000 mockoon/cli:latest -d data -p 3000
Payload to reproduce
Browsing directly to http://localhost:3000/static/%2F..%2F..%2F..%2F..%2F..%2Fetc%2Fpasswd is going to display the /etc/passwd file in the container filesystem
Impact
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2025-59049 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (9.2.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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@mockoon/commons-server to 9.2.0 or later; @mockoon/cli to 9.2.0 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2025-59049? CVE-2025-59049 is a high-severity path traversal vulnerability in @mockoon/commons-server (npm), affecting versions <= 9.1.0. It is fixed in 9.2.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2025-59049? CVE-2025-59049 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2025-59049?
@mockoon/commons-server(npm) (versions <= 9.1.0)@mockoon/cli(npm) (versions <= 9.1.0)
- Is there a fix for CVE-2025-59049? Yes. CVE-2025-59049 is fixed in 9.2.0. Upgrade to this version or later.
- Is CVE-2025-59049 exploitable, and should I be worried? Whether CVE-2025-59049 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-59049 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-59049?
- Upgrade
@mockoon/commons-serverto 9.2.0 or later - Upgrade
@mockoon/clito 9.2.0 or later
- Upgrade