Nginx Proxy ManagerWeb server / proxy · Jc21

CVE-2025-50579

MEDIUM · 5.3 CVSS v3.1 Published 2025-08-19
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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
A CORS misconfiguration in Nginx Proxy Manager v2.12.3 allows unauthorized domains to access sensitive data, particularly JWT tokens, due to improper validation of the Origin header. This misconfiguration enables attackers to intercept tokens using a simple browser script and exfiltrate them to a remote attacker-controlled server, potentially leading to unauthorized actions within the application.

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 confidence

A CORS misconfiguration in Nginx Proxy Manager v2.12.3 allows unauthorized domains to access sensitive data due to improper validation of the Origin header. Attackers can exploit this by tricking authenticated users into visiting malicious pages that execute browser scripts to intercept and exfiltrate JWT tokens to attacker-controlled servers.

MitigationConfigure proper CORS header validation in Nginx Proxy Manager to strictly whitelist trusted domains and reject unauthorized Origins, ensuring JWT tokens cannot be accessed via cross-origin requests.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Nginx Proxy ManagerWeb server / proxy
Affected:= 2.12.3

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
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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. Verify Nginx Proxy Manager version
    Check the installed version of Nginx Proxy Manager (typically via docker container label, package manager, or admin dashboard 'About' section)
    Affected if Version is exactly 2.12.3 (the only affected version listed)
  2. Identify CORS-enabled proxy hosts
    In the Nginx Proxy Manager admin interface, review all proxy hosts and identify which ones have CORS headers enabled in the 'Advanced' or 'CORS' configuration tab
    Affected if Any proxy host has CORS settings configured
  3. Inspect CORS Origin validation configuration
    For each CORS-enabled proxy host, examine the 'Allowed Origins' or 'Access-Control-Allow-Origin' setting - check if it accepts a wildcard (*), multiple unspecified domains, or uses a loose pattern that could match arbitrary domains
    Affected if Origin validation is set to accept any domain, uses a wildcard, or lacks strict domain whitelisting
  4. Test Origin header processing
    Send a test request to a CORS-configured proxy endpoint with a malicious or arbitrary Origin header (e.g., Origin: http://attacker.com) and inspect the Access-Control-Allow-Origin response header
    Affected if The response returns the arbitrary Origin in Access-Control-Allow-Origin without rejecting the request
  5. Check for credential-inclusive CORS policies
    Inspect whether Access-Control-Allow-Credentials is set to true alongside a wildcard or multiple allowed Origins
    Affected if Access-Control-Allow-Credentials is true and Access-Control-Allow-Origin is not explicitly limited to a single trusted domain

If Nginx Proxy Manager version 2.12.3 is running with CORS enabled and the Origin header validation accepts arbitrary or non-whitelisted domains, the environment is vulnerable to cross-origin token theft.

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

Configure proper CORS header validation in Nginx Proxy Manager to strictly whitelist trusted domains and reject unauthorized Origins, ensuring JWT tokens cannot be accessed via cross-origin requests.

Fix this in Nginx Proxy Manager Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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Scan for this in your stack

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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-2025-50579 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data