What is CVE-2017-16086?

CVE-2017-16086 is a high-severity uncontrolled resource consumption vulnerability in ua-parser (npm), affecting versions <= 0.3.5. No fixed version is listed yet. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.

Which versions of ua-parser are affected by CVE-2017-16086?

ua-parser (npm) versions <= 0.3.5 is affected.

Is there a fix for CVE-2017-16086?

No fixed version is listed for CVE-2017-16086 yet. Monitor the advisory for updates and apply mitigations in the interim.

Is CVE-2017-16086 exploitable, and should I be worried?

Whether CVE-2017-16086 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-2017-16086 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-2017-16086?

No fixed version is listed yet. In the interim: Apply input size limits and request rate limiting. Reject input that exceeds reasonable bounds before processing begins.

CVE-2017-16086 in ua-parser

Q: Which versions of ua-parser are affected by CVE-2017-16086?

ua-parser (npm) versions <= 0.3.5 is affected.

Q: Is there a fix for CVE-2017-16086?

No fixed version is listed for CVE-2017-16086 yet. Monitor the advisory for updates and apply mitigations in the interim.

Q: Is CVE-2017-16086 exploitable, and should I be worried?

Whether CVE-2017-16086 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-2017-16086 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-2017-16086?

No fixed version is listed yet. In the interim: Apply input size limits and request rate limiting. Reject input that exceeds reasonable bounds before processing begins.

CVE-2017-16086

CVE-2017-16086 is a high-severity uncontrolled resource consumption vulnerability in ua-parser (npm), affecting versions <= 0.3.5. No fixed version is listed yet.

Does this CVE actually affect you?

Kodem shows which CVEs are reachable and running in your applications, so you fix what's exploitable, not just what's listed.

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Runtime intelligence, not another scanner.

Summary

ReDoS via long UserAgent header in ua-parser

Affected versions of ua-parser are vulnerable to regular expression denial of service when given a specially crafted User-Agent header.

Impact

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

Affected versions

ua-parser (<= 0.3.5)

Security releases

Not available

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

No patch is currently available for this vulnerability.

The best mitigation is currently to avoid using this package, using a different, functionally equivalent package such as useragent.

Frequently Asked Questions

What is CVE-2017-16086? CVE-2017-16086 is a high-severity uncontrolled resource consumption vulnerability in ua-parser (npm), affecting versions <= 0.3.5. No fixed version is listed yet. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
Which versions of ua-parser are affected by CVE-2017-16086? ua-parser (npm) versions <= 0.3.5 is affected.
Is there a fix for CVE-2017-16086? No fixed version is listed for CVE-2017-16086 yet. Monitor the advisory for updates and apply mitigations in the interim.
Is CVE-2017-16086 exploitable, and should I be worried? Whether CVE-2017-16086 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-2017-16086 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-2017-16086? No fixed version is listed yet. In the interim: Apply input size limits and request rate limiting. Reject input that exceeds reasonable bounds before processing begins.