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Websphere Application ServerApplication · Ibm

CVE-2026-9311

CRITICAL · 9.0 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 →
99/100
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 WebSphere Application Server 9.0, and 8.5 is vulnerable to remote code execution caused by the bypass of security controls.

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

IBM WebSphere Application Server versions 8.5 and 9.0 contain a vulnerability that allows remote code execution through bypass of security controls. The vulnerability is exploitable over the network without authentication, as indicated by the critical CVSS score of 9.

MitigationApply IBM WebSphere security patches or interim fixes (iFixes) specific to this vulnerability. Review and harden security configurations to prevent the identified security control bypass.

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
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

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

  1. Locate WebSphere installation directory
    Check common installation paths such as /opt/IBM/WebSphere/AppServer, C:\IBM\WebSphere\AppServer, or the path defined during installation. Also check the WAS_INSTALL_ROOT environment variable.
    Affected if WebSphere is installed on the system
  2. Identify installed WebSphere version
    Run the versionInfo command from the bin directory: cd [install_dir]/bin && ./versionInfo.sh (Linux/Unix) or versionInfo.bat (Windows). Alternatively, check the file [install_dir]/properties/version/NRProductVersion.properties for the exact version number.
    Affected if The displayed or file-contained version falls within 8.5.0.0 to 8.5.5.29 OR 9.0.0.0 to 9.0.5.28
  3. Verify admin console accessibility
    Check if the WebSphere administrative console is exposed to network. Access https://[hostname]:9043/ibm/console or http://[hostname]:9060/ibm/console from a restricted admin workstation to confirm the service is running.
    Affected if The admin console responds without requiring immediate authentication credentials, indicating the service is active and potentially reachable
  4. Confirm patch level against safe versions
    Compare the minor version number from step 2: for 8.5.x, the fix is in 8.5.5.30 and above; for 9.0.x, the fix is in 9.0.5.29 and above. Versions below these thresholds are affected.
    Affected if Installed version is less than 8.5.5.30 for 8.5.x releases OR less than 9.0.5.29 for 9.0.x releases

The environment is affected if IBM WebSphere Application Server version 8.5.0.0 through 8.5.5.29 or 9.0.0.0 through 9.0.5.28 is installed and running.

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 IBM WebSphere security patches or interim fixes (iFixes) specific to this vulnerability. Review and harden security configurations to prevent the identified security control bypass.

Recommended fix High confidence

IBM WebSphere Application Server 9.0.5.29 (or 8.5.5.30) or later

  1. 1. Backup the current IBM WebSphere Application Server configuration and all deployed applications.
  2. 2. Review IBM WebSphere Application Server 9.0.5.29 (or 8.5.5.30) release notes for migration requirements and compatibility notices.
  3. 3. Stop all WebSphere Application Server processes and nodes.
  4. 4. If using IBM Installation Manager, update the package repository and install version 9.0.5.29 (or 8.5.5.30) or later.
  5. 5. Alternatively, download and install the fix pack from IBM Fix Central (https://www.ibm.com/support/fixcentral/).
  6. 6. After installation, start the deployment manager and node agents.
  7. 7. Run the updateConfig script to synchronize nodes with the new installation.
  8. 8. Verify all deployed applications start successfully.
Caveat Review release notes for potential incompatibilities with existing applications; some deprecated features may require code changes

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

Fix this in Websphere Application Server Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA4.0 h
40.0 hours of engineering $7,000
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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-2026-9311 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