CVE-2026-44578 — next
HIGHCVE-2026-44578 is a high-severity (CVSS 8.6) Server-Side Request Forgery (SSRF) vulnerability in next. 3 public exploit references exist, so weaponization risk is real. A fix is available for next — see the affected versions and patch details below.
Next.js: Server-side request forgery in applications using WebSocket upgrades
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-2026-44578.
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-2026-44578 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 10–50% 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
Self-hosted applications using the built-in Node.js server can be vulnerable to server-side request forgery through crafted WebSocket upgrade requests. An attacker can cause the server to proxy requests to arbitrary internal or external destinations, which may expose internal services or cloud metadata endpoints. Vercel-hosted deployments are not affected.
Fix
We now apply the same safety checks to WebSocket upgrade handling that already existed for normal HTTP requests, so upgrade requests are only proxied when routing has explicitly marked them as safe external rewrites.
Workarounds
If you cannot upgrade immediately, do not expose the origin server directly to untrusted networks. If WebSocket upgrades are not required, block them at your reverse proxy or load balancer, and restrict origin egress to internal networks and metadata services where possible.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | next | ≥ 13.4.13&&< 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 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
ynsmroztas/nextssrf
NextSSRF — CVE-2026-44578 Scanner & Exploit ║ ║ Next.js WebSo
dinosn/CVE-2026-44578
CVE-2026-44578: Next.js WebSocket Upgrade SSRF — pre-auth credential the
love07oj/nextjs-cve-2026-44578
Nuclei templates for detecting CVE-2026-44578 (Next.js WebSocket Upgrade
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-2026-44578 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-2026-44578 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44578. 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 Important severity flaw in Next.js affects self-hosted applications, including Red Hat AMQ, when using the built-in Node.js server. A remote attacker can exploit specially crafted WebSocket upgrade requests to perform Server-Side Request Forgery, potentially exposing internal network services or sensitive cloud…
| 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-2026-44578 in your dependencies?
O3 Security finds CVE-2026-44578 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.