CVE-2026-42336
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedMaxKB is an open-source AI assistant for enterprise. MaxKB 2.8.0 and prior are vulnerable to a server-side request forgery (SSRF) bypass in the OSS file service URL fetch functionality due to inconsistent DNS resolution between validation and actual request execution, allowing attackers to access internal network services. This vulnerability is fixed in 2.8.1.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceMaxKB versions 2.8.0 and prior contain an SSRF bypass vulnerability in the OSS file service URL fetch feature. The vulnerability stems from inconsistent DNS resolution between the validation phase and actual request execution, allowing attackers to bypass validation checks and access internal network services.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- Low
- Authentication
- X
- User interaction
- None
- Scope
- X
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/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
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify MaxKB installation versionLocate the version file or use the package management system to query the installed MaxKB version. Common locations include a VERSION file, package.json, or running a version command provided by the application.Affected if The installed version is 2.8.0 or any version prior to 2.8.1
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Locate OSS file service configurationSearch for configuration files related to OSS (Object Storage Service) integration. Look for settings that enable or configure external URL fetching for file services.Affected if OSS file service URL fetch functionality is enabled in the configuration
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Verify DNS resolution behaviorTest the URL fetch feature with a controlled DNS resolution scenario to observe if the validation phase and request execution resolve the same hostname to different IP addresses.Affected if DNS resolution differs between validation and execution phases, allowing internal network access
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Check network access controlsReview network policies, firewall rules, and application-level restrictions governing outbound connections from the server hosting MaxKB.Affected if The server can make outbound HTTP requests to arbitrary URLs without proper filtering
A MaxKB installation is affected if it runs version 2.8.0 or prior and has OSS file service URL fetch functionality enabled, as the DNS resolution inconsistency between validation and execution allows SSRF bypass to internal services.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade MaxKB to version 2.8.1 or later to address the DNS resolution inconsistency. Additionally, implement network segmentation to limit exposure of internal services.
2.8.1
- Upgrade MaxKB to version 2.8.1 or later to resolve the SSRF bypass vulnerability in the OSS file service URL fetch functionality.
- Verify the upgrade by checking the MaxKB version after installation.
- If using a package manager or container deployment, update your deployment configuration to reference version 2.8.1.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-42336 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-42336 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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