CVE-2026-13773
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 · uneditedIBM WebSphere Extreme Scale 8.6.1.0 through 8.6.1.6 Approximately 50 generated CORBA stub classes in WebSphere eXtreme Scale's ogclient.jar call ORB.string_to_object() on an attacker-controlled IOR string during Java deserialization, turning any unfiltered ObjectInputStream sink in WAS into outbound IIOP SSRF to an attacker-chosen host; when chained with the IBM ORB's getUserException class-instantiation flaw (WAS-26), this SSRF escalates to remote code execution on the calling 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 confidenceApproximately 50 generated CORBA stub classes in IBM WebSphere eXtreme Scale's ogclient.jar (versions 8.6.1.0-8.6.1.6) call ORB.string_to_object() on attacker-controlled IOR strings during Java deserialization, creating an outbound IIOP SSRF to an attacker-chosen host. When chained with the IBM ORB getUserException class-instantiation flaw (WAS-26), this SSRF escalates to remote code execution on the calling JVM.
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>= 8.6.1.0, <= 8.6.1.6CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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 checksWork through these to decide whether this CVE applies to you.
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Identify WebSphere eXtreme Scale installation and versionLocate the ogclient.jar file in the WebSphere eXtreme Scale installation directory, then examine the JAR manifest or version metadata to determine the installed version numberAffected if The installed version is 8.6.1.0 through 8.6.1.6 inclusive
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Confirm ogclient.jar presenceSearch for ogclient.jar in the installation directories and verify it is the specific version associated with the affected WebSphere eXtreme Scale releaseAffected if ogclient.jar exists and originates from version 8.6.1.0-8.6.1.6
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Check for deserialization filters on ObjectInputStream usageInspect application code and configuration that deserializes data from untrusted sources, looking for ObjectInputStream implementations that lack a deserialization filter (such as setObjectInputFilter)Affected if ObjectInputStream is used to deserialize untrusted data without a configured deserialization filter
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Verify IIOP/ORB configuration exposureReview network configuration and ORB settings to determine if outbound IIOP connections are permitted and if the Java ORB is configured to accept IOR strings from external sourcesAffected if IIOP outbound connections are allowed and ORB.string_to_object() can be invoked with attacker-controlled IOR strings without validation
You are affected if WebSphere eXtreme Scale version 8.6.1.0-8.6.1.6 is installed AND deserialization filters are not applied to ObjectInputStream sinks that process untrusted data containing IOR strings.
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.
From vendor dataUpgrade to a patched version beyond 8.6.1.6; if immediate upgrade is not feasible, implement network segmentation to block outbound IIOP/IIOP traffic and review all deserialization sinks for untrusted IOR string handling.
- Consultation12.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-13773 — 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-2026-13773 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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- Version or environment caveats, and links to real fixes
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