CVE-2026-5842 — 9router
CVE-2026-5842 is a CWE-285 vulnerability in 9router. A fix is available for 9router — see the affected versions and patch details below.
decolua 9router Administrative API Endpoint api authorization
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2026-5842.
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.
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.
9routernpmDescription
A security vulnerability has been detected in decolua 9router up to 0.3.47. The impacted element is an unknown function of the file /api of the component Administrative API Endpoint. The manipulation leads to authorization bypass. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.75 is sufficient to resolve this issue. It is suggested to upgrade the affected component.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | 9router | all versions | 0.3.75npm install 9router@0.3.75 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for 9router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update 9router to 0.3.75 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-5842 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 CVE-2026-5842 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-5842. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-5842 in your dependencies?
O3 Security finds CVE-2026-5842 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.