Summary
High severity vulnerability that affects gun
Urgent Upgrade
The static file server module included with GUN had a serious vulnerability:
- Using
curl --path-as-isallowed reads on any parent directory or files.
This did not work via the browser or via curl without as-is option.
Fixed
This has been fixed since version 0.2019.416 and higher.
Who Was Effected?
Most NodeJS users who use the default setup, such as:
npm startnode examples/http.jsHeroku1-click-deployDockerNow
If you have a custom NodeJS code then you are probably safe unless you have something like require('http').createServer(Gun.serve(__dirname)) in it.
If you have not upgraded, it is mandatory or else it is highly likely your environment variables and AWS (or other) keys could be leaked.
Credit
It was reported and fixed by JK0N, but I did not understand the --path-as-is condition.
Joonas Loppi from function61 rediscovered it and explained the urgency to me to fix it.
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.
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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-886V-MM6P-4M66? GHSA-886V-MM6P-4M66 is a high-severity path traversal vulnerability in gun (npm), affecting versions < 0.2019.416. It is fixed in 0.2019.416. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of gun are affected by GHSA-886V-MM6P-4M66? gun (npm) versions < 0.2019.416 is affected.
- Is there a fix for GHSA-886V-MM6P-4M66? Yes. GHSA-886V-MM6P-4M66 is fixed in 0.2019.416. Upgrade to this version or later.
- Is GHSA-886V-MM6P-4M66 exploitable, and should I be worried? Whether GHSA-886V-MM6P-4M66 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 GHSA-886V-MM6P-4M66 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 GHSA-886V-MM6P-4M66? Upgrade
gunto 0.2019.416 or later.