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PatchSiren cyber security CVE debrief

CVE-2026-5516 IBM CVE debrief

IBM WebSphere Application Server Liberty 22.0.0.11 through 26.0.0.5 contains a medium-severity timing window vulnerability that could allow remote attackers to bypass security controls under limited conditions. The vulnerability requires high attack complexity and high privileges to exploit, with network access but no user interaction needed. Successful exploitation results in high confidentiality impact (information disclosure) with no integrity or availability impact. The CVE was published on 2026-05-27 and is currently undergoing analysis in the NVD. IBM has published a security bulletin with remediation guidance.

Vendor
IBM
Product
WebSphere Application Server - Liberty
CVSS
MEDIUM 4.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-27
Original CVE updated
2026-06-02
Advisory published
2026-05-27
Advisory updated
2026-06-02

Who should care

Organizations running IBM WebSphere Application Server Liberty versions 22.0.0.11 through 26.0.0.5, particularly those with externally exposed administrative interfaces or multi-tenant deployments where privilege boundaries are critical.

Technical summary

A timing window vulnerability in IBM WebSphere Application Server Liberty 22.0.0.11 through 26.0.0.5 allows remote attackers with high privileges to bypass security controls under limited conditions. The attack requires high complexity and network access, resulting in potential information disclosure (C:H) without affecting integrity or availability. The root cause appears to be a race condition or synchronization issue in security enforcement that can be exploited during a specific timing window.

Defensive priority

medium

Recommended defensive actions

  • Review IBM security bulletin for available fixes and upgrade to a patched version of WebSphere Application Server Liberty
  • Assess exposure of Liberty deployments within the affected version range (22.0.0.11 through 26.0.0.5)
  • Monitor IBM support pages for updated security patches as the vulnerability is undergoing analysis
  • Implement network segmentation and access controls to limit exposure of administrative interfaces
  • Review application logs for anomalous access patterns that may indicate attempted exploitation of timing windows

Evidence notes

CVSS 3.1 vector: AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N. Affected versions: 22.0.0.11 through 26.0.0.5. Vendor confirmed via IBM PSIRT.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-5516 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-5516

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-5516 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-5516

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.