Websphere Extreme ScaleApplication · Ibm

CVE-2026-9002

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-30
Fix available
A fix is available. Upgrade to after 8.6.1.6 or later.
See remediation →
70/100
Remediation priority · Elevated
No privileges Zero-click 7 weeks old

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
IBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 could allow an adjacent attacker to cause a denial of service due to improper validation in the XDF decoder. The application processes deeply nested Protocol Buffers messages and attacker-controlled length prefixes without sufficient bounds checking, which may allow an attacker on the same network to trigger a StackOverflowError or OutOfMemoryError, resulting in a crash of the WebSphere Application Server JVM.

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 · high confidence

IBM WebSphere Extreme Scale versions 8.6.1.0 through 8.6.1.6 contain a vulnerability in the XDF decoder component. The decoder fails to perform adequate bounds checking when processing deeply nested Protocol Buffers messages with attacker-controlled length prefixes. An adjacent attacker on the same network can send specially crafted Protocol Buffer data to trigger either a StackOverflowError (from excessive recursive depth) or an OutOfMemoryError (from unbounded length prefix processing), causing the WebSphere Application Server JVM to crash.

MitigationUpgrade to IBM WebSphere Extreme Scale version 8.6.1.7 or later which contains the patch for proper bounds validation in the XDF decoder. As an interim control, restrict network access to the affected systems to prevent adjacent attackers from reaching the vulnerable decoder component.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Websphere Extreme ScaleApplication
Affected:>= 8.6.1.0, <= 8.6.1.6

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

CVSS:3.1/AV:A/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. Confirm IBM WebSphere Extreme Scale installation
    Run the command 'lsproduct' or check for IBM Extreme Scale installation directories such as /opt/IBM/WebSphere/eXtremeScale or the product's versionInfo command
    Affected if The product is not installed or the installation directory cannot be found, then this CVE does not apply
  2. Determine installed version
    Execute the product version command, typically found in the bin directory of the installation (e.g., versionInfo or aboutInfo) or inspect the manifest files in the installation directory
    Affected if The installed version falls within 8.6.1.0 through 8.6.1.6 inclusive; versions outside this range are not affected
  3. Verify XDF decoder is in use
    Inspect the configuration files (such as the/objectgrid.xml or bmk.xml files) for XDF (eXtreme Scale Data Format) decoder configuration, and check for any protobuf-based data parsing in application logs or deployed configurations
    Affected if The XDF decoder is enabled and processing Protocol Buffer data; if XDF is not configured or not being used, the vulnerability is not reachable
  4. Check network exposure
    Review firewall rules, network ACLs, and the listener configuration to determine if the XDF decoder endpoint is accessible from adjacent network segments or untrusted interfaces
    Affected if The system is accessible from adjacent network attackers (no network segmentation or firewall restrictions), making exploitation possible

A user is affected if IBM WebSphere Extreme Scale version 8.6.1.0 through 8.6.1.6 is installed, the XDF decoder component is enabled and processing Protocol Buffer data, and the affected endpoint is reachable from adjacent network attackers.

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
Upgrade available Upgrade to a release after 8.6.1.6
Interim mitigation

Upgrade to IBM WebSphere Extreme Scale version 8.6.1.7 or later which contains the patch for proper bounds validation in the XDF decoder. As an interim control, restrict network access to the affected systems to prevent adjacent attackers from reaching the vulnerable decoder component.

Fix this in Websphere Extreme Scale Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
Get the upgrade done

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Scan for this in your stack

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dbcve dependency scanner

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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-2026-9002 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data