dbcve.org
Open RedirectWeakness · CWE-601

CVE-2026-10839

MEDIUM · 5.1 CVSS v4.0 Published 2026-06-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable No privileges

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 · unedited
Open redirection vulnerability in the authentication system allows an attacker to use manipulated values in the X-Forwarded-Host header to alter the URLs generated by the application. A successful exploit could redirect authenticated users to malicious sites following login procedures or interaction with the interface, resulting in 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 · moderate confidence

Open redirection vulnerability in the authentication system where the application trusts and uses the X-Forwarded-Host HTTP header to generate redirect URLs without proper validation. Attackers can manipulate this header to cause authenticated users to be redirected to attacker-controlled malicious sites after login or during interface interactions.

MitigationImplement strict allowlist validation for X-Forwarded-Host header values against trusted domains, or remove reliance on this header for redirect URL generation and use only internally-defined trusted domains.

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify if the application processes X-Forwarded-Host header
    Review web server (nginx, Apache, IIS) and application configuration files for any directive that reads or passes the X-Forwarded-Host header. Search configuration files for 'X-Forwarded-Host' or proxy-related settings.
    Affected if The application or web server is configured to read and use the X-Forwarded-Host header value for any URL construction.
  2. Locate redirect URL generation logic
    Search application source code for functions that construct redirect URLs (look for 'redirect', 'Location', 'header', 'url' in combination). Identify where the X-Forwarded-Host header value is incorporated into redirect destinations.
    Affected if Code exists that takes the X-Forwarded-Host header value and includes it in redirect URL construction without validation.
  3. Check for host validation or allowlist logic
    Review the redirect generation code for any validation checks on the host value. Look for allowlist, whitelist, or domain validation functions that restrict redirect targets to predefined trusted domains.
    Affected if No validation, allowlist, or domain restriction exists on the X-Forwarded-Host value before it is used in redirect URLs.
  4. Verify the authentication flow uses this header
    Examine the login and session management code paths. Determine if after successful authentication, the application performs a redirect using a host derived from the X-Forwarded-Host header.
    Affected if After login or during authenticated interface interactions, the application redirects users to a URL constructed using the X-Forwarded-Host header value.
  5. Test for header injection
    Send a request with a crafted X-Forwarded-Host header containing an external domain (e.g., X-Forwarded-Host: malicious.com) and observe if the application redirects to that domain after authentication or during a session action.
    Affected if The application accepts and uses arbitrary X-Forwarded-Host values, causing redirects to attacker-controlled domains.

The environment is affected if the application uses the X-Forwarded-Host header value to construct redirect URLs without validating it against an allowlist of trusted domains.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict allowlist validation for X-Forwarded-Host header values against trusted domains, or remove reliance on this header for redirect URL generation and use only internally-defined trusted domains.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-10839 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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