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Full vulnerability report · 2026
CVE-2026-11537High confidence

IBM WebSphere Application Server prior to 9.0.5.29 and 8.5.5.31 are affected by multiple vulnerabilities

IBM · WebSphere Application Server

4.3MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 0.18% for the current model date.

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

  1. Confirm that the asset runs IBM WebSphere Application Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-83041

No EUVD known-exploited evidence

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
4.3 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

What

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

Why

The server contains a protection mechanism that assumes that any URI that is accessed using HTTP GET will not cause a state change to the associated resource. This might allow attackers to bypass intended access restrictions and conduct resource modification and deletion attacks, since some applications allow GET to modify state.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

What

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

Why

The server contains a protection mechanism that assumes that any URI that is accessed using HTTP GET will not cause a state change to the associated resource. This might allow attackers to bypass intended access restrictions and conduct resource modification and deletion attacks, since some applications allow GET to modify state.

How

An attacker operating through an adjacent network may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

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
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

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 → Trusting HTTP Permission Methods on the Server Side → obtain information outside the intended access boundary
Attack surface
Adjacent
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
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-650 ↗

CWE-650: Trusting HTTP Permission Methods on the Server Side. The server contains a protection mechanism that assumes that any URI that is accessed using HTTP GET will not cause a state change to the associated resource. This might allow attackers to bypass intended access restrictions and conduct resource modification and deletion attacks, since some applications allow GET to modify state.

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:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Common 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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.
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.
UnauthenticatedCWE-650
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-83041Official EUVD mapping

IBM WebSphere Application Server 9.0, and 8.5 could allow a remote attacker to obtain sensitive information about the file system through the FileTransfer servlet.

Official EUVD record ↗
BSI · German · WID-SEC-2026-3255IBM WebSphere Application Server: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in IBM WebSphere Application Server ausnutzen, um Sicherheitsmaßnahmen zu umgehen, Berechtigungen zu erweitern, vertrauliche Informationen offenzulegen, Daten zu manipulieren, Cross-Site-Scripting-Angriffe durchzuführen oder Denial-of-Service-Zustände herbeizuführen.

Official advisory ↗
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
WebSphere Application Server: 9.0, 8.5
Fixed
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 18 Sept 2026 · Last source change 19 Sept 2026, 14:11 UTC · CWE-650 · Trusting HTTP Permission Methods on the Server Side

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-09-19
European sourceENISA EUVD · EUVD-2026-83041
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. ENISA EUVD mappingEUVD-2026-83041 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-83041"}
    ENISA EUVD ↗
  2. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
  3. Vendor guidanceAuthoritative vendor guidance changed: added remediation: ibm.com/7286610.
    Before
    no authoritative guidance recorded
    After
    remediation: ibm.com/7286610
    CNA ↗
  4. Affected versionsThe structured affected or fixed version information changed.
    Before
    WebSphere Application Server: 9.0, 8.5 · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    WebSphere Application Server: 9.0, 8.5 · Fixed: IBM strongly recommends addressing the vulnerabilities now by applying the fix pack(s) listed below.; For IBM WebSphere Application Server traditional:; For V9.0.0.0 through 9.0.5.28:; · Apply Fix Pack 9.0.5.29 SB0030823 (availability September 2026) or later fix pack.; For V8.5.0.0 through 8.5.5.30:; · Apply Fix Pack 8.5.5.31 https://www.ibm.com/support/pages/node/7285869 (availability September 2026) or later fix pack.
    CNA ↗
  5. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-83041↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
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.
Free version - for non-commercial use only.CVE-2026-11537 · cve.blacktree.nl