CVE-2017-16137

Regular Expression Denial of Service in debug

Affected versions of debug are vulnerable to regular expression denial of service when untrusted user input is passed into the o formatter.

As it takes 50,000 characters to block the event loop for 2 seconds, this issue is a low severity issue.

This was later re-introduced in version v3.2.0, and then repatched in versions 3.2.7 and 4.3.1.

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

CVE-2017-16137 has a CVSS score of 3.7 (Low). 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 (2.6.9, 3.1.0, 3.2.7, 4.3.1); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Version 2.x.x: Update to version 2.6.9 or later.
Version 3.1.x: Update to version 3.1.0 or later.
Version 3.2.x: Update to version 3.2.7 or later.
Version 4.x.x: Update to version 4.3.1 or later.

1. What is CVE-2017-16137? CVE-2017-16137 is a low-severity uncontrolled resource consumption vulnerability in debug (npm), affecting versions < 2.6.9. It is fixed in 2.6.9, 3.1.0, 3.2.7, 4.3.1. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2017-16137? CVE-2017-16137 has a CVSS score of 3.7 (Low). 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.
3. Which versions of debug are affected by CVE-2017-16137? debug (npm) versions < 2.6.9 is affected.
4. Is there a fix for CVE-2017-16137? Yes. CVE-2017-16137 is fixed in 2.6.9, 3.1.0, 3.2.7, 4.3.1. Upgrade to this version or later.
5. Is CVE-2017-16137 exploitable, and should I be worried? Whether CVE-2017-16137 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
6. What actually determines whether CVE-2017-16137 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.
7. How do I fix CVE-2017-16137?
   • Upgrade debug to 2.6.9 or later
   • Upgrade debug to 3.1.0 or later
   • Upgrade debug to 3.2.7 or later
   • Upgrade debug to 4.3.1 or later

Other vulnerabilities in debug