CVE-2026-21451CWE-79

Bagisto has HTML Filter Bypass that Enables Stored XSS

Medium · published January 2, 2026

CVSS v4.0
5.2
EPSS
1%
Percentile
45.6
In the wild
Unconfirmed
What it is

⚠️ A crafty bypass in the CMS page editor could let attackers store malicious scripts in Bagisto before version 2.3.10! 💻 Think of it like a restaurant that serves food but lets someone slip a secret ingredient into the sauce before it reaches the table. The unsuspecting diner ends up with a dish that could make them very sick! If an attacker gets control, they can hijack accounts, mess with the backend, and execute harmful scripts, putting not just the admin at risk, but potentially every single user. It's like handing over the keys to the kingdom because you thought the front door was secure!

Put simply

Think of it like a restaurant that serves food but lets someone slip a secret ingredient into the sauce before it reaches the table. The unsuspecting diner ends up with a dish that could make them very sick! This stored XSS vulnerability occurs because Bagisto's CMS page editor attempts to sanitize `<script>` tags, but the filtering can be bypassed through crafted HTTP POST requests, allowing malicious JavaScript to be stored and executed.

What to do

If an attacker gets control, they can hijack accounts, mess with the backend, and execute harmful scripts, putting not just the admin at risk, but potentially every single user. It's like handing over the keys to the kingdom because you thought the front door was secure! Upgrade Bagisto to version 2.3.10 immediately to patch this vulnerability. Additionally, review any existing CMS content for suspicious scripts and educate your team about safe content practices. Tighten input validation wherever possible! You can fix this! With the right steps, you'll ensure your Bagisto site is secure and ready to provide a safe shopping experience. 🛡️

The record
Technical detail
CVSS v4.0
5.2 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:P
EPSS
0.00557 · 45.6th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-01-02T20:37Z
EPSS history
Timeline
  • 02 JAN 20:37Z
    Bagisto has HTML Filter Bypass that Enables Stored XSS
    cvelistv5