CVE-2026-40255 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in @adonisjs/http-server. A fix is available for @adonisjs/http-server — see the affected versions and patch details below.
@adonisjs/http-server has an Open Redirect vulnerability
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-40255.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
@adonisjs/http-servernpm@adonisjs/corenpmDescription
Impact
The response.redirect().back() method in @adonisjs/http-server is vulnerable to open redirects. The method reads the Referer header from the incoming HTTP request and redirects to that URL without validating the host. An attacker who can influence the Referer header (for example, by linking a user through an attacker-controlled page before a form submission) can cause the application to redirect users to a malicious external site.
This affects all AdonisJS applications that use response.redirect().back() or response.redirect('back').
The vulnerability is classified as CWE-601: URL Redirection to Untrusted Site ('Open Redirect').
Patches
This has been fixed in @adonisjs/http-server version 8.2.0. The back() method now validates the Referer header's host against the request's own Host header. Referrers from unrecognized hosts are rejected and the redirect falls back to / (or a developer-provided fallback URL).
Applications that operate across multiple domains can configure additional trusted hosts via the redirect.allowedHosts option in config/app.ts.
Users should upgrade to @adonisjs/http-server@^8.2.0 (or @adonisjs/core@^7.4.0 if using the core meta-package).
Workarounds
If upgrading is not immediately possible, avoid using response.redirect().back() in routes that are reachable by unauthenticated users or from pages that accept external traffic. Instead, redirect to a known safe path explicitly using response.redirect().toPath('/dashboard').
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @adonisjs/http-server | ≥ 8.0.0-next.0&&< 8.2.0 | 8.2.0npm install @adonisjs/http-server@8.2.0 |
| 📦npm | @adonisjs/core | all versions | 7.3.1npm install @adonisjs/core@7.3.1 |
| 📦npm | @adonisjs/http-server | all versions | 7.8.1npm install @adonisjs/http-server@7.8.1 |
Affected Products
coreadonisjshttp-serveradonisjsDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @adonisjs/http-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @adonisjs/http-server to 8.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-40255 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.
Frequently Asked Questions
Is CVE-2026-40255 in your dependencies?
Find it across npm, including transitive dependencies.