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Websphere Application ServerApplication · Ibm

CVE-2026-9330

HIGH · 8.5 CVSS v3.1 Published 2026-06-01
Fix available
A fix is available. Upgrade to 8.5.5.30 / 9.0.5.29 or later.
See remediation →
91/100
Remediation priority · Urgent
Remotely reachable 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
IBM WebSphere Application Server 9.0, and 8.5 is affected by an improper validation of user-supplied data during deserialization using the SAML Web Single Sign-On component. This could result in remote code execution via a crafted HTTP request when combined with a suitable gadget chain.

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 Application Server versions 8.5 and 9.0 contain a deserialization vulnerability in the SAML Web Single Sign-On component due to improper validation of user-supplied data. An unauthenticated attacker can send a crafted HTTP request containing malicious serialized objects, and when combined with a suitable gadget chain, achieve remote code execution on the target system.

MitigationApply the relevant IBM WebSphere security patch or upgrade to a patched version. If immediate patching is not feasible, restrict network access to the SAML Web SSO endpoints and implement additional input validation layers at the application or network level.

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 Application ServerApplication
Affected:>= 8.5.0.0, < 8.5.5.30>= 9.0.0.0, < 9.0.5.29

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
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:L/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 checks

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

  1. Identify WebSphere Application Server installation and version
    Run the versionInfo.sh script in the WebSphere installation bin directory, or check the installation directory for version files. Common paths: <WAS_HOME>/bin/versionInfo.sh
    Affected if The installed version is 8.5.0.0 through 8.5.5.29, or 9.0.0.0 through 9.0.5.28 (these versions are within the affected range)
  2. Determine if SAML Web SSO feature is installed
    Check the installed features using versionInfo.sh -showDetail, or examine the profile configuration for SAML SPNEGO or SAML Web SSO extensions in the WAS admin console under Security > SAML Web SSO
    Affected if SAML Web Single Sign-On feature is installed and configured on the application server
  3. Verify SAML SSO is enabled for applications
    Check application deployment descriptors or the WebSphere admin console under Security > Global Security > Web and SIP security > Single Sign-On to see if SAML Web SSO is enabled
    Affected if SAML Web SSO is enabled and applications are configured to use it for authentication
  4. Assess network exposure of SAML endpoints
    Review web server and network configuration to determine if SAML assertion consumer service endpoints (typically /saml) are exposed to untrusted network sources
    Affected if SAML endpoints are accessible from untrusted or public networks without proper access controls

You are affected if WebSphere Application Server version falls within 8.5.0.0-8.5.5.29 or 9.0.0.0-9.0.5.28 AND the SAML Web SSO component is installed and enabled, with endpoints exposed to potential 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.

dbcve · scoped
Upgrade available Upgrade to 8.5.5.30 / 9.0.5.29 or later
Fixed in 8.5.5.309.0.5.29
Interim mitigation

Apply the relevant IBM WebSphere security patch or upgrade to a patched version. If immediate patching is not feasible, restrict network access to the SAML Web SSO endpoints and implement additional input validation layers at the application or network level.

Recommended fix Moderate confidence

WebSphere 8.5.5.30+ or 9.0.5.29+

  1. 1. Identify the current WebSphere Application Server version by checking the installation directory or admin console.
  2. 2. For WebSphere 8.5.x installations: Plan an upgrade to version 8.5.5.30 or later.
  3. 3. For WebSphere 9.0.x installations: Plan an upgrade to version 9.0.5.29 or later.
  4. 4. Review IBM WebSphere Application Server fix central for the appropriate interim fix or upgrade package.
  5. 5. Schedule a maintenance window and backup the current WebSphere configuration.
  6. 6. Apply the upgrade or install the interim fix following IBM's standard WebSphere patching procedures.
  7. 7. Restart the WebSphere Application Server services after applying the update.
  8. 8. Verify the SAML Web Single Sign-On functionality is working correctly after the update.
Caveat Standard upgrade risks apply - test thoroughly in non-production environment first; review IBM's migration guides for any configuration changes needed

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Websphere Application Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2026-9330 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