GHSA-9vvw-cc9w-f27h is a high-severity (CVSS 7.5) CWE-1333 vulnerability in debug. 2 public exploit references exist, so weaponization risk is real. A fix is available for debug — see the affected versions and patch details below.
debug Inefficient Regular Expression Complexity vulnerability
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 GHSA-9vvw-cc9w-f27h.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-9vvw-cc9w-f27h plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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.
debugnpmDescription
A vulnerability classified as problematic has been found in debug-js debug up to 3.0.x. This affects the function useColors of the file src/node.js. The manipulation of the argument str leads to inefficient regular expression complexity. Upgrading to version 3.1.0 is able to address this issue. The name of the patch is c38a0166c266a679c8de012d4eaccec3f944e685. It is recommended to upgrade the affected component. The identifier VDB-217665 was assigned to this vulnerability. The patch has been backported to the 2.6.x branch in version 2.6.9.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | debug | ≥ 3.0.0&&< 3.1.0 | 3.1.0npm install debug@3.1.0 |
| 📦npm | debug | all versions | 2.6.9npm install debug@2.6.9 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
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 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9vvw-cc9w-f27h is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9vvw-cc9w-f27h can be triaged on real exposure rather than presence alone.
Tailored to GHSA-9vvw-cc9w-f27h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-9vvw-cc9w-f27h in your dependencies?
O3 Security finds GHSA-9vvw-cc9w-f27h across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.