Is CVE-2026-39422 in the CISA KEV catalog?

No. CVE-2026-39422 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-39422?

CVE-2026-39422 has a CVSS v3 base score of 5.4 (MEDIUM).

What is the EPSS score for CVE-2026-39422?

CVE-2026-39422 has an EPSS score of 0.22% (12th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-39422?

Upgrade maxkb to 2.8.0 or later.

CVE & CISA-KEV Catalog

CVE-2026-39422

MEDIUM

5.4

CVSS v3

NVD

Description

MaxKB is an open-source AI assistant for enterprise. Versions 2.7.1 and below contain a Stored Cross-Site Scripting (XSS) vulnerability through the application name or icon fields when creating an application. When a victim visits the public chat interface (/ui/chat/{access_token}), the ChatHeadersMiddleware retrieves the application data and directly inserts the unescaped application name and icon into the HTML response via string replacement. This allows an attacker to execute arbitrary JavaScript in the victim's browser context. This issue has been fixed in version 2.8.0.

CWE-79Cross-Site Scripting (XSS)

How to fix

Remediation Available

maxkbNVD

Affected:< 2.8.0Fixed in:2.8.0CVE-2026-39422derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionRequired

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

0.22%probability of exploitation in 30 days

12thpercentile

Low risk: more likely to be exploited than 12% of all known CVEs.

References

Patch1

github.com

Exploit1

github.com

Release Notes1

github.com

Related Vulnerabilities

Other CWE-79 (Cross-Site Scripting (XSS)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-11022	Medium	6.9	99%	-	Fix
CVE-2019-3929	Critical	9.8	99%	KEV	Fix
CVE-2020-9496	Medium	6.1	99%	-	-
CVE-2023-28341	Medium	6.1	99%	-	Fix
CVE-2018-12998	Medium	6.1	98%	-	-
CVE-2025-4123	High	7.6	98%	-	Fix

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Markdown

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HTML

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-20.