What is CVE-2026-55100?

CVE-2026-55100 is a high-severity security vulnerability in hashi-vault-js (npm), affecting versions <= 0.5.1. It is fixed in 0.5.2.

Which versions of hashi-vault-js are affected by CVE-2026-55100?

hashi-vault-js (npm) versions <= 0.5.1 is affected.

Is there a fix for CVE-2026-55100?

Yes. CVE-2026-55100 is fixed in 0.5.2. Upgrade to this version or later.

Is CVE-2026-55100 exploitable, and should I be worried?

Whether CVE-2026-55100 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.

What actually determines whether CVE-2026-55100 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-2026-55100?

Upgrade hashi-vault-js to 0.5.2 or later.

CVE-2026-55100 in hashi-vault-js

Q: Which versions of hashi-vault-js are affected by CVE-2026-55100?

hashi-vault-js (npm) versions <= 0.5.1 is affected.

Q: Is there a fix for CVE-2026-55100?

Yes. CVE-2026-55100 is fixed in 0.5.2. Upgrade to this version or later.

Q: Is CVE-2026-55100 exploitable, and should I be worried?

Whether CVE-2026-55100 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.

Q: What actually determines whether CVE-2026-55100 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.

Q: How do I fix CVE-2026-55100?

Upgrade hashi-vault-js to 0.5.2 or later.

Summary

hashi-vault-js has a path traversal and query parameter injection

The hashi-vault-js library is vulnerable to path traversal and query string injection due to the lack of proper encoding of identifiers in path segments and query strings. This allows attackers to manipulate the request URL and potentially access unintended downstream endpoints or inject malicious parameters if untrusted input is passed to the library.

Details

There are zero calls to encodeURIComponent anywhere in Vault.js. Every identifier (e.g., name, username, group, role, version) provided to the library is concatenated straight into the HTTP URL without URI encoding.

Two vectors can be dynamically confirmed:

Path Traversal: Passing ../../sys/seal as a secret name causes the HTTP client to normalize the path and send the request to /v1/sys/seal instead of the intended Key-Value path.
Query Injection: Passing 1&list=true as a version value injects an extra query parameter into the request payload.

Workarounds

If you cannot immediately update the library, you can mitigate this issue by rigidly validating and sanitizing all user-supplied input before passing it into hashi-vault-js methods. Alternatively, manually encode inputs using encodeURIComponent() before supply them to the library's functions.

Acknowledgements

hashi-vault-js would like to thank Sebastián Alba Vives for reporting this vulnerability.

Impact

In applications where Vault identifiers originate from untrusted user input, this allows an unauthenticated attacker to redirect requests to unintended Vault endpoints (including administrative paths under sys/) or otherwise alter the executed query, executing operations within the permissions of the Vault token used by the application.

Affected versions

hashi-vault-js (<= 0.5.1)

Security releases

hashi-vault-js → 0.5.2 (npm)

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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Remediation advice

This vulnerability has been addressed by wrapping path segments with encodeURIComponent() and safely formatting query strings instead of manual string concatenation. Users should upgrade to a version that includes this fix.

Frequently Asked Questions

What is CVE-2026-55100? CVE-2026-55100 is a high-severity security vulnerability in hashi-vault-js (npm), affecting versions <= 0.5.1. It is fixed in 0.5.2.
Which versions of hashi-vault-js are affected by CVE-2026-55100? hashi-vault-js (npm) versions <= 0.5.1 is affected.
Is there a fix for CVE-2026-55100? Yes. CVE-2026-55100 is fixed in 0.5.2. Upgrade to this version or later.
Is CVE-2026-55100 exploitable, and should I be worried? Whether CVE-2026-55100 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-2026-55100 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-2026-55100? Upgrade hashi-vault-js to 0.5.2 or later.