CVE-2026-14277: IBM i Access Family RCE Vulnerability

CVE-2026-14277 Overview

CVE-2026-14277 is a command injection vulnerability in IBM i Access Family versions 1.1.2.0 through 1.1.9.15. The flaw stems from improper validation of user-supplied input within a session file. An authenticated user can leverage the weakness to execute arbitrary commands with normal user privileges on the affected system. The vulnerability is classified under CWE-78, Improper Neutralization of Special Elements used in an OS Command.

Critical Impact

An authenticated attacker can execute arbitrary operating system commands under the identity of the invoking user, enabling lateral movement and data access within the scope of that account.

Affected Products

• IBM i Access Family 1.1.2.0
• IBM i Access Family versions 1.1.3.0 through 1.1.9.14
• IBM i Access Family 1.1.9.15

Discovery Timeline

• 2026-09-14 - CVE-2026-14277 published to NVD
• 2026-09-17 - Last updated in NVD database

Technical Details for CVE-2026-14277

Vulnerability Analysis

IBM i Access Family provides client-side connectivity to IBM i (formerly AS/400 and IBM System i) servers. The affected component processes session files that describe display, printer, or transfer session parameters. According to IBM, the client fails to properly validate user-supplied input embedded within a session file before passing that input to an operating system command interpreter.

Because the vulnerable code path handles a session file as trusted configuration data, malicious content placed inside the file is treated as executable command syntax. An attacker who can influence or supply a session file processed by the client triggers command execution in the security context of the user opening the file.

Exploitation requires authentication and low attack complexity, but the resulting execution is limited to normal user privileges rather than administrative rights. Confidentiality, integrity, and availability impacts are each scoped to the user's own environment.

Root Cause

The root cause is missing or insufficient neutralization of shell metacharacters and command separators within fields parsed from session configuration files. Input read from the session file is concatenated into a command string and dispatched to the underlying OS shell without sanitization, matching the [CWE-78] pattern.

Attack Vector

The attack vector is network-adjacent through file delivery. An authenticated attacker crafts a session file containing embedded OS command syntax and delivers it to a target user through file shares, email attachments, or a compromised project directory. When the victim opens the file with IBM i Access Family, the client parses the malicious fields and invokes the injected commands. No verified public exploit is available at the time of publication, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog.

No verified proof-of-concept code is publicly available. See the IBM Support Page for vendor technical details.

Detection Methods for CVE-2026-14277

Indicators of Compromise

• Session files (for example, .ws, .dtf, .dtq, or related IBM i Access session extensions) containing shell metacharacters such as ;, |, &, backticks, or $(...) inside configuration fields.
• Unexpected child processes such as cmd.exe, powershell.exe, or wscript.exe spawned by IBM i Access Family executables.
• Newly modified or attacker-supplied session files placed in user profile directories or shared network locations.

Detection Strategies

• Hunt for process ancestry where IBM i Access Family client binaries are the parent of interpreter or scripting processes.
• Inspect file writes to session file extensions from non-standard sources such as browsers, email clients, or archive utilities.
• Correlate authentication events on IBM i hosts with client process launches to identify anomalous session establishment tied to injected commands.

Monitoring Recommendations

• Enable command-line logging on Windows endpoints running IBM i Access Family and forward events to a centralized analytics platform.
• Alert on IBM i Access Family client versions between 1.1.2.0 and 1.1.9.15 detected in software inventory.
• Monitor egress network activity from IBM i Access Family processes for signs of secondary payload retrieval.

How to Mitigate CVE-2026-14277

Immediate Actions Required

• Identify all endpoints running IBM i Access Family versions 1.1.2.0 through 1.1.9.15 using software asset management data.
• Apply the IBM-provided fix referenced in the vendor advisory as soon as it is validated in a test environment.
• Restrict write access to directories from which users open session files, and treat externally supplied session files as untrusted.

Patch Information

IBM has published remediation guidance on the IBM Support Page. Administrators should upgrade IBM i Access Family to the fixed release identified in that advisory. Verify installed client versions after patching to confirm remediation.

Workarounds

• Block delivery of IBM i Access session file extensions through email gateways and web proxies where operationally feasible.
• Enforce application control policies that prevent IBM i Access Family binaries from spawning command interpreters.
• Require session files to originate from an internal, access-controlled repository rather than user-writable locations.

Refer to the IBM Support Page for vendor-specific configuration guidance.