CVE-2026-45270: CI4MS: Stored XSS in Pages Module Content via Broken html_purify Validation Rule

Summary The Pages backend module registers the html_purify validation rule on language-keyed page content but persists the raw, un-purified POST value into the database. The public renderer for pages (Home::index() → ap…

8.7CVSS Score

HIGHSeverity

NOCISA KEV

VulnerabilityImpact Type

📋 Vulnerability Details

CVE ID	CVE-2026-45270
Vendor	composer
Affected Product	ci4-cms-erp/ci4ms
Vulnerability Type	Vulnerability
CVSS Score	8.7 (HIGH)
Actively Exploited	❌ No known exploitation
Patch Status	See Vendor Advisory →
Reported By	CYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

Summary The `Pages` backend module registers the `html_purify` validation rule on language-keyed page content but persists the raw, un-purified POST value into the database. The public renderer for pages (`Home::index()` → `app/Views/templates/default/pages.php`) emits `$pageInfo->content` without `esc()`, yielding stored XSS that fires for every public visitor of the affected page — including administrators. Because pages may be promoted to the site home page, the payload can be served at `/` and reach every visitor of the site.

Details This is a sibling-module variant of the same root cause as the Blog stored-XSS issue. The `html_purify` custom rule (`modules/Backend/Validation/CustomRules.php:54`) mutates its first argument by reference: ```php

public function html_purify(?string

📚 Advisory References

⚡ DETECTION RULES AVAILABLE

Get CVE-2026-45270 Detection Pack

Sigma rules, YARA signatures, IOC table, and SIEM queries for Splunk, Elastic, Sentinel, and Chronicle — deployable in 5 minutes.

✓ Sigma Rules ✓ YARA Pack ✓ IOC Table ✓ SIEM Queries

🛡️ Get Detection Pack → 🔌 Access via API →