Dashboard / CVE-2026-39426

CVE-2026-39426

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 50/100
Published: 2026-04-14 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: Passive
S: X
AT: None
VC: Low
VI: Low
VA: None

Description

MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a Stored Cross-Site Scripting (XSS) vulnerability where the frontend's MdRenderer.vue component parses custom <iframe_render> tags from LLM responses or Application Prologue configurations, bypassing standard Markdown sanitization and XSS filtering. The unsanitized HTML content is passed to the IframeRender.vue component, which renders it directly into an <iframe> via the srcdoc attribute configured with sandbox="allow-scripts allow-same-origin". This can be a dangerous combination, allowing injected scripts to escape the iframe and execute JavaScript in the parent window using window.parent. Since the Prologue is rendered for any user visiting an application's chat interface, this results in a high-impact Stored XSS that can lead to session hijacking, unauthorized actions, and sensitive data exposure. This issue has been fixed in version 2.8.0.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
maxkb maxkb < 2.8.0

References & Advisories (2)

Bug Bounty Relevance

50 / 100
✓ Network accessible
✓ Low complexity

CVSS Score

5.1 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.19%
Raw Score 0.001930
Percentile 9.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00193
2026-10-28
0.00193

Intelligence Sources

nvd ref →

External Links