Security Bulletin
Summary
IBM i Access Client Solutions (ACS) is affected by multiple vulnerabilities [CVE-2026-94002, CVE-2026-94029] as described in the vulnerability details section.
Vulnerability Details
CVEID: CVE-2026-94002
DESCRIPTION: Possible memory exhaustion in SFTP clients (DefaultSftpClient) in component sshd-sftp in Apache MINA SSHD versions 0.9.0 to 2.19.0 and 3.0.0-M1 to 3.0.0-M5.
Apache
MINA SSHD is a Java library for client-side and server-side SSH. The sshd-sftp component provides support for SFTP.
The SFTP client implementation, when receiving a reply, did not check that this reply corresponded to a request sent earlier. Unsolicited replies would be stored but never consumed. A malicious server could keep sending unsolicited replies until available memory in the client was exhausted.
Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: security@apache.org
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-2026-94029
DESCRIPTION: Server-side memory exhaustion in Apache MINA SSHD 1.0.0 to 2.19.0 and 3.0.0-M1 to 3.0.0-M5, component sshd-sftp, in the SFTP v6 check-file-name/check-file-handle extension. Apache MINA SSHD is a Java library for client-side and server-side SSH.
Using a very small "block size" (for instance 256, which is the minimum) on a huge file generates many (file size / block size) hashes. The resulting SFTP reply message was accumulated fully in memory server-side, which could, with a suitably large (possibly sparse) file exhaust the server-side memory, taking down the server.
Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue by imposing a maximum limit on the size of the reply. Many SFTP implementations have a general limit on the size of SFTP messages anyway; typically 256kB as in OpenSSH or also in Apache MINA SSHD.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: security@apache.org
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| IBM i Access Family | 1.1.9.1 - 1.1.9.16 |
Remediation/Fixes
The issues can be fixed by upgrading to version 1.1.9.17 or later. See IBM i Access Client Solutions updates for the latest version available.
| Product(s) | Version(s) | Remediation/Fix/Instructions | |||||||||||||||
| IBM i Access Client Solutions | 1.1.9.1 - 1.1.9.16 |
There are three ways to obtain the current version of IBM i Access Client Solutions: 1) IBM i Access Client Solutions is available at Downloads. 2) IBM i Access Client Solutions can be downloaded from the general IBM i software site at Entitled Systems Support (ESS).
3) IBM i Access Client Solutions is available by applying a PTF to IBM i.
|
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
20 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
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Document Information
Modified date:
20 October 2026
Initial Publish date:
20 October 2026
UID
ibm17293205