CVE-2016-10703 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in ecstatic. 1 public exploit reference exists, so weaponization risk is real. A fix is available for ecstatic — see the affected versions and patch details below.
Denial of Service in ecstatic
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2016-10703 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
ecstaticnpmDescription
ecstatic, a simple static file server middleware, is vulnerable to denial of service. If a payload with a large number of null bytes (%00) is provided by an attacker it can crash ecstatic by running it out of memory.
Results from the original advisory
A payload of 22kB caused a lag of 1 second,
A payload of 35kB caused a lag of 3 seconds,
A payload of 86kB caused the server to crash
Recommendation
Update to version 2.0.0 or later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ecstatic | all versions | 2.0.0npm install ecstatic@2.0.0 |
Affected Products
ecstaticecstatic_projectResearch 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 ecstatic, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ecstatic to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10703 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.
Frequently Asked Questions
Is CVE-2016-10703 in your dependencies?
Find it across npm, including transitive dependencies.