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Websphere Application ServerApplication · Ibm

CVE-2026-8633

CRITICAL · 9.8 CVSS v3.1 Published 2026-05-26
Fix available
A fix is available. Upgrade to after 9.0.5.27 or later.
See remediation →
100/100
Remediation priority · Urgent
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
IBM Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty 8.5, 9.0 IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to remote code execution in the Web Server Plug-ins, through a specially crafted request.

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 and WebSphere Liberty versions 8.5 and 9.0 contain a remote code execution vulnerability in the Web Server Plug-ins component. The flaw is triggered via specially crafted HTTP requests sent to the web server plugin, allowing attackers to execute arbitrary code on affected systems without authentication.

MitigationApply IBM's available security patches for WebSphere Application Server and WebSphere Liberty to the affected versions. As a temporary control, restrict network access to the web server plugin endpoints to reduce exposure until patching can be completed.

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, <= 8.5.5.29>= 9.0.0.0, <= 9.0.5.27

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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 installation
    Check for IBM WebSphere Application Server or WebSphere Liberty installations on the system by looking for common installation directories or using system inventory tools
    Affected if The product is IBM WebSphere Application Server or WebSphere Liberty
  2. Determine installed version
    Use the WebSphere version detection method appropriate for your installation (such as the versionInfo script or checking product properties) and compare the full version number against the affected ranges: 8.5.0.0-8.5.5.29 or 9.0.0.0-9.0.5.27
    Affected if The installed version falls within 8.5.0.0 through 8.5.5.29 or 9.0.0.0 through 9.0.5.27
  3. Verify web server plug-in is configured
    Check if the IBM WebSphere web server plug-in (typically the plugin-cfg.xml file or corresponding plugin configuration) is present and actively configured for the WebSphere deployment
    Affected if The web server plug-in configuration exists and is active for the installation
  4. Check plug-in network exposure
    Examine network exposure of the web server plug-in by reviewing web server configuration, firewall rules, and network access controls that govern who can send requests to the plug-in components
    Affected if The web server plug-in is accessible from untrusted network segments or the internet

The environment is affected if WebSphere Application Server versions 8.5.0.0-8.5.5.29 or 9.0.0.0-9.0.5.27 are installed with the web server plug-in component enabled and exposed to network access.

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 a release after 9.0.5.27
Interim mitigation

Apply IBM's available security patches for WebSphere Application Server and WebSphere Liberty to the affected versions. As a temporary control, restrict network access to the web server plugin endpoints to reduce exposure until patching can be completed.

Recommended fix Moderate confidence

WebSphere Application Server 8.5.5.30+ or 9.0.5.28+ (or latest available fix pack)

  1. 1. Identify the current WebSphere Application Server version using 'aboutWebSphere.pl' or the admin console.
  2. 2. For version 8.5.x: Schedule a maintenance window and upgrade to version 8.5.5.30 or later.
  3. 3. For version 9.0.x: Schedule a maintenance window and upgrade to version 9.0.5.28 or later.
  4. 4. After upgrade, verify the IHS plugin configuration using the admin console under 'Servers > Server Types > Web servers > web_server_name > Plug-in properties'.
  5. 5. Test application functionality to ensure the plugin upgrade does not break existing integrations.
  6. 6. Monitor IBM's security bulletins for any follow-up patches.
Caveat Upgrade may require regression testing of all web server plugin configurations and IHS/Liberty integrations; review IBM's migration guide for version-specific changes

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

Fix this in Websphere Application Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
24.0 hours of engineering $4,160
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,656.

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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-2026-8633 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