If left unpatched, CVE-2026-40500 could lead to major system disruptions or data loss.
Status: Received on 15 Apr 2026, 22:17 UTC
Published on: 15 Apr 2026, 22:17 UTC
CVSS Release: version 3
disclosure@vulncheck.com
Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
CVE-2026-40500: 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.
The exploitability of CVE-2026-40500 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
The exploitability of CVE-2026-40500 is influenced by multiple factors. Security teams should analyze system configurations and apply appropriate countermeasures to mitigate threats.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2026-40500, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2026-40500, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
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