CVE-2026-71315 is a high-severity (CVSS 8.2) CWE-178 vulnerability in nuxt. A fix is available for nuxt — see the affected versions and patch details below.
Nuxt route rules silently dropped for mixed-case paths, bypassing appMiddleware auth gates (incomplete fix for CVE-2026-53721)
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-2026-71315.
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
CVE-2026-71315 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.
nuxtnpmDescription
Nuxt is an open-source web development framework for Vue.js. From 3.21.7 until 3.21.10 and 4.5.1, mixed-case routeRules keys can fail to match case-folded lookups when router.options.sensitive is false and drop appMiddleware authorization gates. This is caused by an incomplete fix for CVE-2026-53721. This issue is fixed in 3.21.10 and 4.5.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | nuxt | ≥ 4.4.7&&< 4.5.1 | 4.5.1npm install nuxt@4.5.1 |
| 📦npm | nuxt | ≥ 3.21.7&&< 3.21.10 | 3.21.10npm install nuxt@3.21.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nuxt, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nuxt to 4.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-71315 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-2026-71315 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-71315. 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-2026-71315 in your dependencies?
O3 Security finds CVE-2026-71315 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.