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Security Bulletin: IBM Storage Fusion Data Foundation is vulnerable to Denial of Service

Security Bulletin


Summary

fast-xml-parser is used by IBM Storage Fusion Data Foundation, which could cause Denial of Service. (CVE-2026-27942, CVE-2026-26278, CVE-2026-33036)

Vulnerability Details

CVEID:   CVE-2026-27942
DESCRIPTION:   fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.
CWE:   CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CVSS Source:   NVD
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2026-26278
DESCRIPTION:   fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. In versions 4.1.3 through 5.3.5, the XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to make the parser spend seconds or even minutes processing a single request, effectively freezing the application. Version 5.3.6 fixes the issue. As a workaround, avoid using DOCTYPE parsing by `processEntities: false` option.
CWE:   CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CVSS Source:   security-advisories@github.com
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:   CVE-2026-33036
DESCRIPTION:   fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Versions 4.0.0-beta.3 through 5.5.5 contain a bypass vulnerability where numeric character references (&#NNN;, &#xHH;) and standard XML entities completely evade the entity expansion limits (e.g., maxTotalExpansions, maxExpandedLength) added to fix CVE-2026-26278, enabling XML entity expansion Denial of Service. The root cause is that replaceEntitiesValue() in OrderedObjParser.js only enforces expansion counting on DOCTYPE-defined entities while the lastEntities loop handling numeric/standard entities performs no counting at all. An attacker supplying 1M numeric entity references like A can force ~147MB of memory allocation and heavy CPU usage, potentially crashing the process—even when developers have configured strict limits. This issue has been fixed in version 5.5.6.
CWE:   CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
CVSS Source:   security-advisories@github.com
CVSS Base score:   7.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
IBM Fusion Data Foundation
4.14, 4.16, 4.18 - 4.21

Remediation/Fixes

IBM strongly recommends addressing the vulnerability now.

Upgrade IBM Fusion Data Foundation to version 4.22 or later release/patch by following the instructions below.

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Change History

09 Oct 2026: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

[{"Business Unit":{"code":"BU070","label":"IBM Infrastructure"},"Product":{"code":"SSSEWFV","label":"Storage Fusion Data Foundation"},"Component":"","Platform":[{"code":"PF043","label":"Red Hat"},{"code":"PF040","label":"RedHat OpenShift"}],"Version":"4.14, 4.16, 4.18 - 4.21","Edition":"","Line of Business":{"code":"LOB66","label":"Technology Lifecycle Services"}}]

Document Information

Modified date:
09 October 2026

Initial Publish date:
09 October 2026

UID

ibm17291922