CVE-2026-115457 baserCMS: Unauthenticated Stored XSS via Shortcode Expansion in Blog Comments
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-115457?
CVE-2026-115457 is a high-severity vulnerability in baserproject basercms, published on 23 Oct 2026.
Official description
baserCMS is a website development framework. In versions 5.0.0 before 5.3.2 and 5.4.0 before 5.4.2, global shortcode expansion runs over the complete rendered page, including HTML-escaped blog comments supplied by unauthenticated visitors. A comment containing the BcBaser.getGoogleMaps shortcode can set apiBaseUrl to an attacker-controlled script URL, which is emitted as a script src and executes JavaScript on the site's origin when another visitor or administrator opens the article displaying that comment. Escaping raw HTML in comments does not prevent this stored cross-site scripting because shortcode processing happens after HTML rendering. Other registered shortcodes also expand in comments; Mail.getForm can embed a working contact form with a valid CSRF token. The flaw can compromise the authenticated browser context of an administrator who views the affected article. This issue has been patched in versions 5.3.2 and 5.4.2.
Weakness: CWE-79
Which versions are affected by CVE-2026-115457?
How do I fix CVE-2026-115457?
No fix has been published for CVE-2026-115457 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-115457 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-115457 exists.
Sources
Also known as GHSA-qhv2-3j2q-v43x.