CVE-2026-44574 — next
HIGHCVE-2026-44574 is a high-severity (CVSS 8.1) CWE-288 vulnerability in next. A fix is available for next — see the affected versions and patch details below.
Next.js: Middleware / Proxy bypass through dynamic route parameter injection
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2026-44574.
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-2026-44574 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 378,567 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.
nextnpmDescription
Impact
Applications that rely on middleware to protect dynamic routes can be vulnerable to authorization bypass. In affected deployments, specially crafted query parameters can alter the dynamic route value seen by the page while leaving the visible path unchanged, which can allow protected content to be rendered without passing the expected middleware check.
Fix
We now only honor internal route-parameter normalization in trusted routing flows and ignore externally supplied parameter encodings that should never have been accepted from ordinary requests.
Workarounds
If you cannot upgrade immediately, enforce authorization in route or page logic instead of relying solely on middleware path matching.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | next | ≥ 15.4.0&&< 15.5.16 | 15.5.16npm install next@15.5.16 |
| 📦npm | next | ≥ 16.0.0&&< 16.2.5 | 16.2.5npm install next@16.2.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for next, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update next to 15.5.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44574 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-2026-44574 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44574. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
This is an Important authorization bypass flaw in Next.js applications, which are utilized in Red Hat AMQ, Red Hat Trusted Artifact Signer, and Red Hat Enterprise Linux AI. The vulnerability arises when applications use Next.js middleware to protect dynamic routes, allowing attackers to access restricted content by…
| Product | Fixed in | Advisory |
|---|---|---|
| Streams for Apache Kafka 2.9.4 | next | RHSA-2026:34608 |
| Streams for Apache Kafka 3.2.1 | next | RHSA-2026:54435 |
| Red Hat Trusted Artifact Signer 1.3 | rhtas/rekor-search-ui-rhel9:1783958622 | RHSA-2026:40974 |
| Red Hat Trusted Artifact Signer 1.4 | rhtas/rekor-search-ui-rhel9:1783327185 | RHSA-2026:37272 |
Frequently Asked Questions
Is CVE-2026-44574 in your dependencies?
O3 Security finds CVE-2026-44574 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.