CVE-2026-40500: ProcessWire Server-side Request Forgery Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-gmwr-9j4p-96vm
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CVSS 6.8
CWE-918
Published
Advisory Summary

CVE-2026-40500 is a MODERATE (CVSS 6.8) server-side request forgery vulnerability vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting ProcessWire libraries in the Packagist ecosystem. The issue involves server-side request forgery vulnerability in the admin panel's 'add module from url' feature. Remediation is available in the latest vendor maintenance releases.

CVE-2026-40500 at a Glance

CVE Identifier CVE-2026-40500
GHSA Identifier GHSA-gmwr-9j4p-96vm
Severity MODERATE
CVSS v3.1 Base Score 6.8
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product ProcessWire
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-40500

To remediate this vulnerability, upgrade all affected ProcessWire dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

processwire/processwire fixed: Latest secure release 
Upgrade processwire/processwire to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for processwire/processwire

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-40500, inspect your project dependencies for ProcessWire:

inspect dependencies for processwire/processwire

Analyze the terminal output to locate any version of ProcessWire in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. In ProcessWire, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

ProcessWire CMS version 3.0.255 and prior contain a server-side request forgery vulnerability in the admin panel's 'Add Module From URL' feature that allows authenticated administrators to supply arbitrary URLs to the module download parameter, causing the server to issue outbound HTTP requests to attacker-controlled internal or external hosts. Attackers can exploit differentiable error messages returned by the server to perform reliable internal network port scanning, host enumeration across RFC-1918 ranges, and potential access to cloud instance metadata endpoints.

CVE-2026-40500 Affected ProcessWire Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
processwire/processwire
 Packagist
≤ 3.0.255

References

NVD — CVE-2026-40500 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40500
ProcessWire Source Repository REPOSITORY
https://gist.github.com/thepiyushkumarshukla/7514e5eed526fd9d20fcfc42ce8d0a82
ProcessWire Source Repository REPOSITORY
https://github.com/processwire/processwire
ProcessWire Security Information SECURITY
https://processwire.com
www.vulncheck.com/advisories/processw... WEB
https://www.vulncheck.com/advisories/processwire-cms-ssrf-via-add-module-from-url

Frequently Asked Questions

What is CVE-2026-40500?
CVE-2026-40500 is a security vulnerability in ProcessWire involving server-side request forgery vulnerability in the admin panel's 'Add Module From URL' feature under CWE-918: Server-Side Request Forgery (SSRF).
Which ProcessWire versions are affected?
Affected versions include releases prior to current release patches across affected packages: processwire/processwire.
What version fixes CVE-2026-40500?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is processwire/processwire affected?
Yes, processwire/processwire is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-40500?
CVE-2026-40500 has a CVSS v3.1 base score of 6.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2026-40500?
CVE-2026-40500 is classified under CWE-918: Server-Side Request Forgery (SSRF) (The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.).
How can I check Packagist dependencies for CVE-2026-40500?
Run the dependency tree command: 'inspect dependencies for processwire/processwire'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gmwr-9j4p-96vm",
  "modified" : "2026-04-16T22:28:24Z",
  "published" : "2026-04-16T00:54:04Z",
  "aliases" : [ "CVE-2026-40500" ],
  "summary" : "ProcessWire: server-side request forgery vulnerability in the admin panel's 'Add Module From URL' feature",
  "details" : "ProcessWire CMS version 3.0.255 and prior contain a server-side request forgery vulnerability in the admin panel's 'Add Module From URL' feature that allows authenticated administrators to supply arbitrary URLs to the module download parameter, causing the server to issue outbound HTTP requests to attacker-controlled internal or external hosts. Attackers can exploit differentiable error messages returned by the server to perform reliable internal network port scanning, host enumeration across RFC-1918 ranges, and potential access to cloud instance metadata endpoints.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "processwire/processwire"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "3.0.255"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40500"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/thepiyushkumarshukla/7514e5eed526fd9d20fcfc42ce8d0a82"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/processwire/processwire"
  }, {
    "type" : "WEB",
    "url" : "https://processwire.com"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/processwire-cms-ssrf-via-add-module-from-url"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-16T22:28:24Z",
    "nvd_published_at" : "2026-04-15T22:17:22Z"
  }
}