Server-Side Request Forgery (SSRF)Weakness · CWE-918

CVE-2026-36759

MEDIUM · 6.5 CVSS v3.1 Published 2026-04-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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 Server-Side Request Forgery (SSRF) in the /themes/{name}/upgrade-from-uri endpoint of halo v2.22.14 allows authenticated attackers to scan internal resources via a crafted GET request.

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

This is a Server-Side Request Forgery (SSRF) vulnerability in the halo CMS platform. The /themes/{name}/upgrade-from-uri endpoint accepts user-controlled URI input without proper validation, allowing authenticated attackers to make the server perform requests to arbitrary internal or external resources. This can be leveraged to scan internal network services, access cloud metadata endpoints, or interact with internal APIs.

MitigationImplement strict allowlist-based validation for URI inputs, restricting endpoints to only permitted domains/IPs. Additionally, disable or restrict the upgrade-from-uri theme functionality if not required, and apply the latest security patch from the halo project.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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. Identify installed halo CMS version
    Check the application's version by reviewing the halo installation directory, package.json, or the admin interface version information. Compare your installed version against known halo CMS releases.
    Affected if Your halo CMS version is unpatched and the vendor has not released a security update for this vulnerability.
  2. Verify the themes endpoint exists
    Locate the halo CMS web application files and confirm the presence of the theme upgrade routing handlers, specifically the endpoint pattern /themes/{name}/upgrade-from-uri. This is typically found in the routing configuration or controller definitions.
    Affected if The vulnerable endpoint handler exists in your installation and is accessible via the web server.
  3. Confirm authentication is required
    Review your halo CMS authentication configuration to determine if access to the /themes/{name}/upgrade-from-uri endpoint requires valid user credentials. Check user role permissions and session handling settings.
    Affected if The endpoint permits unauthenticated access, meaning any user can trigger the SSRF without credentials.
  4. Check theme installation status
    List all installed themes in your halo CMS instance via the admin panel or by examining the themes directory. The vulnerable endpoint requires a valid theme name parameter.
    Affected if At least one theme is installed and active, providing a valid parameter value for the /themes/{name}/upgrade-from-uri endpoint.

You are affected if your halo CMS version contains the vulnerable endpoint, authentication is misconfigured or bypassed, and a theme is installed that can be used as the path parameter.

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-based validation for URI inputs, restricting endpoints to only permitted domains/IPs. Additionally, disable or restrict the upgrade-from-uri theme functionality if not required, and apply the latest security patch from the halo project.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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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-2026-36759 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
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