Security Bulletin
Summary
IBM Sterling B2B Integrator and IBM Sterling File Gateway have addressed the security vulnerability
Vulnerability Details
CVEID: CVE-2026-47065
DESCRIPTION: ZDRES-232: resolveProxyClass Not Overridden - acceptMatchers Filter Bypass via java.lang.reflect.Proxy
Assessment: Fully addressed.
When the serialised stream contains a TC_PROXYCLASSDESC (the marker
for a java.lang.reflect.Proxy ), JDK’s ObjectInputStream.readProxyDesc()
is
dispatched. JDK then calls the default
ObjectInputStream.resolveProxyClass(interfaces) implementation, which
performs Class.forName(intf, false, latestUserDefinedLoader()) for EACH
interface name and constructs the proxy class — bypassing the accepted
classes list .
ZDRES-233: Class.forName(name, initialize=true, classLoader) in
readClassDescriptor Triggers Static Initialiser of Allow-Listed Classes
Assessment: Fully addressed.
For ANY class on the allow-list, deserialising a stream that names it triggers the class’s
(static initialiser) BEFORE any instance is constructed. This means an
attacker who supplies a class name on the allow-list (e.g., the
developer wrote accept(“com.myapp.*") , attacker supplies
com.myapp.SomeClass ) causes clinit of SomeClass — and many
real-world classes have side-effecting static initialisers
Both issues have been fixed.
CWE: CWE-502: Deserialization of Untrusted Data
CVSS Source: security@apache.org
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM Sterling B2B Integrator | 6.2.0.0 - 6.2.0.6, 6.2.1.0 - 6.2.1.2, 6.2.2.0 - 6.2.2.0_1 |
| IBM Sterling File Gateway | 6.2.0.0 - 6.2.0.6, 6.2.1.0 - 6.2.1.2, 6.2.2.0 - 6.2.2.0_1 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now.
| Product | Version | APAR | Remediation & Fix |
| IBM Sterling B2B Integrator | 6.2.0.0 - 6.2.0.6, 6.2.1.0 - 6.2.1.2, 6.2.2.0 - 6.2.2.0_1 | IT49534 | Apply 6.2.0.6_1, 6.2.1.2_1 or 6.2.2.1 |
| IBM Sterling File Gateway | 6.2.0.0 - 6.2.0.6, 6.2.1.0 - 6.2.1.2, 6.2.2.0 - 6.2.2.0_1 | IT49534 | Apply 6.2.0.6_1, 6.2.1.2_1 or 6.2.2.1 |
The IIM versions 6.2.1.2_1 and 6.2.2.1 are available on Fix Central.
The container versions of 6.2.1.2_1 and 6.2.2.1 are available in IBM Entitled Registry
- cp.icr.io/cp/ibm-b2bi for IBM Sterling B2B Integrator
- cp.icr.io/cp/ibm-sfg for IBM Sterling File Gateway
For 6.2.0.6_1, contact the support
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
17 Sep 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
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Document Information
Modified date:
17 September 2026
Initial Publish date:
17 September 2026
UID
ibm17287962