How severe is CVE-2017-16137?

CVE-2017-16137 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2017-16137?

CVE-2017-16137 affects the following packages: debug (npm), debug (npm), debug (npm), debug (npm). Ecosystems affected: npm.

How do I fix CVE-2017-16137?

Update debug to 2.6.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-16137 is resolved across your whole dependency graph.

How do I detect CVE-2017-16137 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for debug, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2017-16137 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2017-16137 actively exploited in the wild?

No public exploit code has been indexed for CVE-2017-16137 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2017-16137?

CVE-2017-16137 has an EPSS (Exploit Prediction Scoring System) score of 2.8%, placing it in the 87th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2017-16137?

CVE-2017-16137 is classified as Uncontrolled Resource Consumption (CWE-400). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2017-16137 published, and has it been updated?

CVE-2017-16137 was published on June 7, 2018 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2017-16137 — debug

MEDIUMFix: visionmedia/debug#504

CVE-2017-16137 is a medium-severity (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in debug. A fix is available for debug — see the affected versions and patch details below.

Regular Expression Denial of Service in debug

Also known asGHSA-gxpj-cx7g-858c

Published

Jun 7, 2018

Updated

Oct 20, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2017-16137.

EPSS Exploitation Probability

via FIRST.org ↗

2.8%probability of exploitation in next 30 days

Lower Risk-0.04%

Lower risk than most CVEs87th percentile — riskier than 87% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

57Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

debugnpm

458.6Mdownloads / week

Description

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.

Recommendation

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.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`debug`	all versions	2.6.9`npm install debug@2.6.9`
📦npm	`debug`	≥ 3.0.0&&< 3.1.0	3.1.0`npm install debug@3.1.0`
📦npm	`debug`	≥ 3.2.0&&< 3.2.7	3.2.7`npm install debug@3.2.7`
📦npm	`debug`	≥ 4.0.0&&< 4.3.1	4.3.1`npm install debug@4.3.1`

Affected Products

1 product · 2 configurations

Application

debugdebug_project

≥ 3.0.0 && < 3.1.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for debug, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update debug to 2.6.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-16137 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

This issue affects the versions of rh-nodejs4-nodejs-debug, rh-nodejs6-nodejs-debug, and rh-nodejs8-nodejs-debug as shipped with Red Hat Software Collections 3. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to…

Product	Fixed in	Advisory
Red Hat Quay 3	`quay/quay-rhel8:v3.6.0-62`	RHSA-2021:3917

Frequently Asked Questions

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. ## Recommendation 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.

O3 Security · Impact-Aware SCA

Is CVE-2017-16137 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works