CVE-2026-45270 CI4MS: Stored XSS in Pages Module Content via Broken html_purify Validation Rule
Stored XSS in CI4MS Pages module allows attackers to inject scripts that execute for all visitors, including admins, due to missing output escaping.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-45270?
CVE-2026-45270 is a high-severity cross-site scripting vulnerability in ci4-cms-erp ci4ms, published on 20 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
CI4MS is a CodeIgniter 4-based content management system skeleton. Prior to version 0.31.9.0, 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. Version 0.31.9.0 patches the issue.
Weakness: CWE-79
Which versions are affected by CVE-2026-45270?
2 open source packages ship an affected version, including ci4-cms-erp/ci4ms.
| Package | Affected | Fixed in |
|---|---|---|
ci4-cms-erp/ci4ms Packagist | All versions | 0.31.9.0 |
ci4-cms-erp/ci4ms Packagist | All versions | 0.31.9.0 |
How do I fix CVE-2026-45270?
Upgrade ci4-cms-erp/ci4ms to 0.31.9.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-45270 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-45270 exists.
Sources
Also known as GHSA-gqr2-7hcg-rchf.