CVE-2026-27562: Command Injection RCE Vulnerability

CVE-2026-27562 Overview

CVE-2026-27562 is a command injection vulnerability [CWE-78] affecting the /api/iodd/config endpoint on an industrial device covered by CERT-VDE advisories. An authenticated attacker with administrative credentials can send a crafted PUT request to inject operating system commands. Successful exploitation runs arbitrary commands with root privileges on the target device. The vulnerability is exposed over the network and requires no user interaction. CERT-VDE has published three coordinated advisories (VDE-2026-014, VDE-2026-027, and VDE-2026-028) referencing the flaw.

Critical Impact
An admin-authenticated attacker can achieve remote root command execution on affected industrial devices through a single crafted PUT request to the IO-Link device configuration API.

Affected Products

Industrial devices covered by CERT-VDE advisory VDE-2026-014
Industrial devices covered by CERT-VDE advisory VDE-2026-027
Industrial devices covered by CERT-VDE advisory VDE-2026-028

Discovery Timeline

2026-09-16 - CVE-2026-27562 published to NVD
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-27562

Vulnerability Analysis

The vulnerability resides in the handler for the /api/iodd/config endpoint, which manages IO-Link Device Description (IODD) configuration. The handler accepts input from a PUT request and passes attacker-controlled data into an operating system command without proper sanitization or argument separation. This allows shell metacharacters to break out of the intended command context. Because the web service runs as root, injected commands inherit full privileges over the underlying Linux system. The flaw is classified under CWE-78, Improper Neutralization of Special Elements used in an OS Command.

Root Cause

The root cause is unsafe construction of a shell command string using unvalidated fields from the JSON body of the PUT /api/iodd/config request. The application concatenates request parameters directly into a command executed by a system shell rather than using a parameterized process invocation. No input allowlisting, escaping, or command-argument separation is performed before execution.

Attack Vector

Exploitation requires network access to the device management interface and valid administrator credentials. The attacker sends a PUT request to /api/iodd/config with a payload that embeds shell metacharacters (for example, ;, |, `, or $()) inside a configuration field. The backend passes the payload to a shell, executing the injected commands as root. The Elevated Privileges Required rating reflects the need for admin credentials, but any compromise or reuse of admin credentials converts this into full device takeover.

No verified public exploit code is available. See the CERT-VDE Advisory VDE-2026-014, CERT-VDE Advisory VDE-2026-027, and CERT-VDE Advisory VDE-2026-028 for vendor-specific technical details.

Detection Methods for CVE-2026-27562

Indicators of Compromise

PUT requests to /api/iodd/config containing shell metacharacters such as ;, |, &&, `, or $() in JSON body fields.
Unexpected child processes spawned by the device web service, particularly shells (sh, bash) or utilities like wget, curl, nc, or busybox invoking outbound connections.
New or modified files under writable paths such as /tmp, /var/tmp, or persistence locations following an admin API session.
Outbound connections from the device to previously unseen hosts shortly after configuration API activity.

Detection Strategies

Inspect HTTP request bodies to /api/iodd/config for shell metacharacters and non-conforming values in configuration fields.
Baseline expected process trees for the device management daemon and alert on any deviation, especially shell invocations.
Correlate administrative API authentication events with subsequent process execution and outbound network activity to identify abuse of legitimate credentials.

Monitoring Recommendations

Forward device syslog, web server logs, and authentication events to a centralized platform for retention and correlation.
Monitor administrator logins to the device from unusual source IPs, off-hours sessions, and repeated PUT requests to configuration endpoints.
Track outbound egress from operational technology segments to detect command-and-control activity following successful injection.

How to Mitigate CVE-2026-27562

Immediate Actions Required

Apply firmware updates referenced in CERT-VDE advisories VDE-2026-014, VDE-2026-027, and VDE-2026-028 as soon as they are available for your device model.
Rotate all administrator credentials on affected devices and remove shared or default accounts.
Restrict network access to the device management interface to a dedicated engineering workstation or jump host.
Audit recent PUT requests to /api/iodd/config and administrative logins for signs of exploitation.

Patch Information

Fixed firmware versions and patch availability are published in the CERT-VDE advisories. Refer to the CERT-VDE Advisory VDE-2026-014, CERT-VDE Advisory VDE-2026-027, and CERT-VDE Advisory VDE-2026-028 for the specific vendor, product, and firmware versions addressed by this fix.

Workarounds

Place affected devices behind a firewall that allows management access only from an allowlisted engineering network segment.
Disable remote administrative access where it is not operationally required and enforce access through a bastion host.
Enforce multi-factor authentication on any upstream jump host used to reach the device management interface, since the device itself requires admin credentials for exploitation.
Monitor and rate-limit requests to /api/iodd/config at an upstream reverse proxy or industrial firewall until patched firmware is deployed.