CVE-2026-10837
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpen redirection vulnerability due to insufficient validation of the X-Forwarded-Host HTTP header. An attacker could create manipulated links that, when opened by a victim, cause the victim to be redirected to domains controlled by the attacker, enabling phishing or deception attacks with limited impact on confidentiality and integrity.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOpen redirection vulnerability due to insufficient validation of the X-Forwarded-Host HTTP header. The application uses this header value to determine redirect destinations without proper allowlist validation, allowing attackers to specify arbitrary attacker-controlled domains that victims will be redirected to.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- Authentication
- X
- User interaction
- A
- Scope
- X
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if X-Forwarded-Host header processing is enabledSearch application configuration files and code for any usage of 'X-Forwarded-Host' header. Look for patterns like request.getHeader('X-Forwarded-Host'), req.headers['x-forwarded-host'], or equivalent in your language/framework. Check proxy configurations (e.g., nginx, Apache, load balancers) that may forward this header.Affected if The application reads or trusts the X-Forwarded-Host header for any purpose
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Locate redirect functionality that uses host header valuesSearch the codebase for redirect methods (e.g., response.redirect(), header('Location:'), return RedirectResponse()) that incorporate host or domain values. Identify which redirects use the X-Forwarded-Host or similar host headers as part of the destination URL.Affected if Redirect logic uses the X-Forwarded-Host header value to construct the Location URL
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Examine redirect logic for allowlist validationReview the redirect code identified in step 2 to determine if it validates the domain against an explicit allowlist of permitted domains before performing the redirect. Look for validation functions that check if the host matches predefined safe domains.Affected if No allowlist validation exists, or the redirect accepts any domain from the X-Forwarded-Host header without restriction
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Test redirect behavior with arbitrary X-Forwarded-Host valueSend a request with an arbitrary domain in the X-Forwarded-Host header (e.g., X-Forwarded-Host: attacker.com) and observe if the application redirects to that domain. Use curl -H 'X-Forwarded-Host: example.com' <target-url> and check the Location response header or final destination.Affected if The application redirects to the attacker-controlled domain specified in the X-Forwarded-Host header
User is affected if the application uses the X-Forwarded-Host header to determine redirect destinations without strict allowlist validation of permitted domains.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement strict allowlist validation for X-Forwarded-Host header values, rejecting any domains not explicitly permitted, or disable trust in this header if not required by the application architecture.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-10837 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-10837 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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