Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.69% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-4410High confidence
IBM WebSphere Application Server and WebSphere Application Server Liberty are affected by a denial of service
IBM · WebSphere Application Server - Liberty
4.8MediumCVSS 3.1
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs IBM WebSphere Application Server - Liberty and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
IBM WebSphere Application Server - Liberty 19.0.0.7 through 26.0.0.5 and IBM WebSphere Application Server 9.0, and 8.5 and WebSphere Application Server Liberty are vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consume memory resources.
What
IBM WebSphere Application Server - Liberty 19.0.0.7 through 26.0.0.5 and IBM WebSphere Application Server 9.0, and 8.5 and WebSphere Application Server Liberty are vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consume memory resources.
Why
The product does not properly control the allocation and maintenance of a limited resource.
How
An attacker operating through an adjacent network may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
What
IBM WebSphere Application Server - Liberty 19.0.0.7 through 26.0.0.5 and IBM WebSphere Application Server 9.0, and 8.5 and WebSphere Application Server Liberty are vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consume memory resources.
Why
The product does not properly control the allocation and maintenance of a limited resource.
How
An attacker operating through an adjacent network may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- an adjacent network → Uncontrolled Resource Consumption → disrupt the affected service
- Attack surface
- Adjacent
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-400 ↗
CWE-400: Uncontrolled Resource Consumption. The product does not properly control the allocation and maintenance of a limited resource.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Affected
- Fixed
- IBM strongly recommends addressing the vulnerability now by applying a currently available interim fix or fix pack that contains the fix for APAR PH70807 and APAR PH70616. To determine if a feature is enabled for WebSphere Application Server Liberty, refer to How to determine if Liberty is using a specific feature https://www.ibm.com/support/pages/node/6553910 .
- For IBM WebSphere Application Server Liberty 19.0.0.7 - 26.0.0.5 using the sipServlet-1.1 feature:
- · Upgrade to minimal fix pack levels as required by the interim fix and then apply the Interim Fix that resolves PH70807 https://www.ibm.com/support/pages/node/7273237
- --OR--
- · Apply Fix Pack 26.0.0.6 or later (targeted availability 2Q2026).
- For IBM WebSphere Application Server traditional:
- For V9.0.0.0 through 9.0.5.27:
- · Upgrade to minimal fix pack levels as required by the interim fix and then apply the Interim Fix that resolves PH70616 https://www.ibm.com/support/pages/node/7269402
- · Apply Fix Pack 9.0.5.28 or later (targeted availability 2Q2026).
- For V8.5.0.0 through 8.5.5.29:
- · Upgrade to minimal fix pack levels as required by interim fix and then apply Interim Fix that resolves PH70616 https://www.ibm.com/support/pages/node/7269402
- · Apply Fix Pack 8.5.5.30 or later (targeted availability 3Q2026).
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 27 May 2026 · Last source change 27 May 2026, 15:25 UTC · CWE-400 · Uncontrolled Resource Consumption
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-32281
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.