CVE-2026-39423 Stored XSS via Eval Injection in EchartsRander Component
Attackers can inject JavaScript into the AI chat interface, leading to stored XSS and potential account takeover in MaxKB.
- 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
- None listed
What is CVE-2026-39423?
CVE-2026-39423 is a medium-severity cross-site scripting vulnerability in 1Panel-dev MaxKB, published on 14 Apr 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
MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain an Eval Injection vulnerability in the Markdown rendering engine that allows any user capable of interacting with the AI chat interface to execute arbitrary JavaScript in the browsers of other users, including administrators, resulting in Stored Cross-Site Scripting (XSS). This issue has been fixed in version 2.8.0.
Which versions are affected by CVE-2026-39423?
It affects 1 product.
Products include Maxkb Maxkb.
How do I fix CVE-2026-39423?
No fix has been published for CVE-2026-39423 yet. Limit exposure of the affected software until one is available.
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-2026-39423 being exploited?
There is no known exploitation of CVE-2026-39423 in the wild and no public exploit code.
Other vulnerabilities in 1Panel-dev MaxKB
- CVE-2025-66419 MaxKB vulnerable to privilege escalation through sandbox bypass
- CVE-2025-66446 MaxKB has a Python sandbox LD_PRELOAD bypass
- CVE-2025-64511 MaxKB has SSRF in sandbox
- CVE-2026-39422 MaxKB has Stored XSS via ChatHeadersMiddleware
- CVE-2024-56137 MaxKB RCE vulnerability in function library
Sources
Also known as GHSA-462x-99gf-mp79.