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Improper Input ValidationWeakness · CWE-20

CVE-2026-36501

HIGH · 7.5 CVSS v3.1 Published 2026-06-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
An issue in the Externalizable.readExternal() component of Controller v12.0.5 allows attackers to cause a Denial of Service (DoS) via a crafted input.

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 confidence

The vulnerability exists in the Externalizable.readExternal() method of Controller v12.0.5. Attackers can send crafted serialized input that causes the application to crash or become unresponsive, resulting in Denial of Service. This is a Java deserialization issue where improper input validation during the readExternal() deserialization process allows malformed data to trigger resource exhaustion or unhandled exceptions.

MitigationImplement strict input validation and bounds checking within the readExternal() method, add comprehensive exception handling to prevent crashes from malformed data, and consider implementing an allowlist of permitted classes for deserialization.

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
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Controller product installation and version
    Locate the Controller installation directory and check the version file or product metadata. Typical locations include /opt/controller, /usr/local/controller, or C:\Program Files\Controller. Look for version.txt, build.properties, or similar version indicators.
    Affected if The installed version is Controller v12.0.5 or any earlier version that includes the vulnerable readExternal() implementation
  2. Verify Java deserialization is enabled
    Check application configuration files (such as web.xml, application.properties, or custom config files) for serialization settings. Look for ObjectInputStream usage or configuration enabling Java remote method invocation (RMI) or other serialization-based communication.
    Affected if Java deserialization is enabled and the application accepts serialized objects through network endpoints or file upload mechanisms
  3. Identify Externalizable class usage
    Search the application codebase for classes implementing java.io.Externalizable interface. Review the readExternal() method implementation to see if it performs proper input validation and exception handling before processing deserialized data.
    Affected if The application uses classes implementing Externalizable with a readExternal() method that lacks proper input validation and bounds checking
  4. Check network exposure of deserialization endpoints
    Review network-facing configurations and determine if the application exposes endpoints that accept serialized Java objects. Check logs for any attempted or successful deserialization requests from external sources.
    Affected if The application accepts serialized Externalizable objects from untrusted network sources without validation
  5. Review existing exception handling in deserialization path
    Examine the readExternal() method code (if accessible) or review exception logs to determine if malformed input triggers unhandled exceptions that crash or hang the application.
    Affected if The readExternal() method lacks comprehensive exception handling and malformed data causes application crashes or resource exhaustion

A user is affected if they have Controller v12.0.5 (or earlier) installed with Java deserialization enabled and Externalizable classes accepting untrusted input without proper validation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement strict input validation and bounds checking within the readExternal() method, add comprehensive exception handling to prevent crashes from malformed data, and consider implementing an allowlist of permitted classes for deserialization.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-36501 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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