CVE-2026-39426 (GCVE-0-2026-39426)
Vulnerability from cvelistv5 – Published: 2026-04-14 01:25 – Updated: 2026-04-14 01:25
VLAI?
Title
MaxKB: Stored XSS via Unsanitized iframe_render Parsing
Summary
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.
Severity ?
CWE
- CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
| URL | Tags | |||||||
|---|---|---|---|---|---|---|---|---|
|
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Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| 1Panel-dev | MaxKB |
Affected:
< 2.8.0
|
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"vendor": "1Panel-dev",
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}
],
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"baseScore": 5.1,
"baseSeverity": "MEDIUM",
"privilegesRequired": "LOW",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "LOW",
"subIntegrityImpact": "LOW",
"userInteraction": "PASSIVE",
"vectorString": "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",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
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"problemTypes": [
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"cweId": "CWE-79",
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"shortName": "GitHub_M"
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},
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"url": "https://github.com/1Panel-dev/MaxKB/releases/tag/v2.8.0"
}
],
"source": {
"advisory": "GHSA-q2qg-43vq-f2wv",
"discovery": "UNKNOWN"
},
"title": "MaxKB: Stored XSS via Unsanitized iframe_render Parsing"
}
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"cveId": "CVE-2026-39426",
"datePublished": "2026-04-14T01:25:10.592Z",
"dateReserved": "2026-04-07T00:23:30.596Z",
"dateUpdated": "2026-04-14T01:25:10.592Z",
"state": "PUBLISHED"
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}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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