CI4MS has stored XSS via srcdoc attribute bypass in Google Maps iframe setting

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-39390: 0.24% estimated exploitation activity in the next 30 days; percentile 14.56 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The Google Maps iframe setting (cMap field) in compInfosPost() sanitizes input using striptags() with an <iframe allowlist and regex-based removal of on\w+ event handlers. However, the srcdoc attribute is not an event handler and passes all filters. An attacker with admin settings access can inject an <iframe srcdoc="..." payload with HTML-entity-encoded JavaScript that executes in the context of the parent page when rendered to unauthenticated frontend visitors. Details Input sanitization (modules/Settings/Controllers/Settings.php:49-53): The three regex patterns only match attributes beginning with on (e.g., onclick, onerror). The srcdoc attribute does not begin with on and passes through untouched. Output rendering (app/Views/templates/default/gmapiframe.php:3): The output applies striptags with the same <iframe allowlist but performs no attribute filtering or HTML encoding. The stored payload is rendered verbatim. Why HTML entities bypass striptags: A payload like <iframe…

Published by the source

8 Apr 2026, 19:15 UTC

Last modified by the source

8 Apr 2026, 19:15 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x3hr-cp7x-44r2

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# Patch Next advisory brief: CVE-2026-39390

Advisory: CI4MS has stored XSS via srcdoc attribute bypass in Google Maps iframe setting
IDs: CVE-2026-39390, GHSA-x3hr-cp7x-44r2
Record: https://patchnext.com/advisories/cve-2026-39390 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: ci4-cms-erp/ci4ms 0.31.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist ci4-cms-erp/ci4ms: affected <= 0.31.3.0; fixed in 0.31.4.0

## Suggested inspection (read-only)
- Packagist ci4-cms-erp/ci4ms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on ci4-cms-erp/ci4ms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x3hr-cp7x-44r2 (GitHub-reviewed advisory GHSA-x3hr-cp7x-44r2 lists affected ranges: Packagist ci4-cms-erp/ci4ms >=0 <=0.31.3.0)

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