Advisory · CVE-2026-15266
IBM Concert can run arbitrary system commands from crafted input
IBM Concert 1.0 through 3.0.1.1 contains components that allow potentially unsafe command execution, which could be exploited to run arbitrary system commands on the host, rated critical at CVSS 9.8.
- Vendor
- IBM
- Product
- Concert
- Identifier / CWE
- CVE-2026-15266
CWE-78 - Action timing
- Immediate
Explain it like I’m five
IBM Concert takes input and, in some of its components, passes it toward the operating system without enough checking. An attacker can shape that input so the host runs their commands instead.
- 01Crafted input sent
An attacker sends input to a Concert component.
- 02Validation skipped
The input reaches an operating system command without adequate sanitization.
- 03Commands executed
Arbitrary system commands run on the host.
What happened
IBM Concert 1.0 through 3.0.1.1 contains components that allow potentially unsafe command execution, which could be exploited to run arbitrary system commands on the host. The record rates it critical at CVSS 9.8 under version 3.1, with network attack vector, low complexity, no privileges required, and no user interaction.
IBM’s bulletin lists the affected versions and the fix. Unauthenticated command execution on the host is a complete compromise of the Concert deployment.
What to do
- Inventory Concert deployments and record each version.
- Check the IBM bulletin for the fix and apply it.
- Review host and application logs for unexpected command execution.
- Treat the host as potentially compromised if exploitation cannot be excluded.
- Verify the deployed version after updating.
Management note
Unauthenticated remote code execution needs no further analysis to justify patching. Assume the host was reachable and check the logs.