CVE-2026-9336

Filesystem exhaustion via unauthenticated administrative endpoint

Published Sep 10, 2026 · Updated Sep 10, 2026

Denial of service in IBM WebSphere Application Server 8.5 and 9.0 allows remote attackers to exhaust filesystem space via HTTP. The administrative endpoint accepts the crafted request without authentication and consumes filesystem space, but IBM has not disclosed the handler or stored data. Network adjacency is required, and successful exploitation can halt server operation as filesystem capacity is depleted.

CVSS severity6.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in IBM WebSphere Application Server 8.5 and 9.0 allows remote attackers to exhaust filesystem space via HTTP. The administrative endpoint accepts the crafted request without authentication and consumes filesystem space, but IBM has not disclosed the handler or stored data. Network adjacency is required, and successful exploitation can halt server operation as filesystem capacity is depleted.

The record

CVE
CVE-2026-9336
Published
Sep 10, 2026
Updated
Sep 10, 2026
Vendor
IBM
Product
IBM WebSphere Application Server
Classifications
CWE-306, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=8.5
  2. Affected versionversion=9.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

IBM · IBM WebSphere Application Serverversion=8.5; version=9.0

Published CVSS scores

6.5IBMCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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