Review reviewCritical

CVE-2026-9311

IBM WebSphere Application Server, websphere application server

IBM WebSphere Application Server 9.0, and 8.5 is vulnerable to remote code execution caused by the bypass of security controls.

CVSS
9
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.06.02
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9

Vulnerability overview

IBM WebSphere Application Server 9.0, and 8.5 is vulnerable to remote code execution caused by the bypass of security controls.

Affected product and versions

Product
IBM WebSphere Application Server, websphere application server
Affected versions
>= 9.0 <= 1.1.9.12, >= 8.5, >= 8.5.0.0 < 8.5.5.30, >= 9.0.0.0 < 9.0.5.29
Fixed versions
8.5.5.30, 9.0.5.29

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that IBM WebSphere Application Server, websphere application server and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CWE
CWE-94
CVE-2026-9311 — IBM WebSphere Application Server, websphere application server | SECUFOCUS NOW