CVE-2026-42336Network attack vector

Authenticated SSRF via separate DNS resolutions

Published May 26, 2026 · Updated May 26, 2026

SSRF in MaxKB before 2.8.1 allows remote authenticated users to reach internal network services through the OSS URL fetch endpoint. The /chat/api/oss/get_url handler checks socket.gethostbyname() before requests.get() performs a separate DNS lookup, so DNS rebinding defeats the private-address check. A low-privileged account and control of DNS answers are required; successful requests can read or modify data exposed by reachable internal services.

CVSS severity5.1
Medium
EPSS probability0.19%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in MaxKB before 2.8.1 allows remote authenticated users to reach internal network services through the OSS URL fetch endpoint. The /chat/api/oss/get_url handler checks socket.gethostbyname() before requests.get() performs a separate DNS lookup, so DNS rebinding defeats the private-address check. A low-privileged account and control of DNS answers are required; successful requests can read or modify data exposed by reachable internal services.

The record

CVE
CVE-2026-42336
Published
May 26, 2026
Updated
May 26, 2026
Vendor
KubeOperator
Product
MaxKB
Classifications
CWE-918, CWE-367, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 2.8.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

KubeOperator · MaxKBversion=< 2.8.1

Published CVSS scores

5.1GitHub, Inc.CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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