CVE-2026-40500

MEDIUMCVSS 6.1/10EPSS 0.39%

Last modified

CVE-2026-40500 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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.. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
6.8/10

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

CVSS 4.0
6.1/10

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/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

EPSS Probability
0.39%

30.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is 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.
How severe is CVE-2026-40500?
CVE-2026-40500 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2026-40500?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-40500?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST