RCE in IBM Concert

CVE-2026-6721

IBM Concert 1.0.0 through 3.0.0 allows an unauthenticated remote attacker can supply specially crafted input that is incorporated into OS commands, resulting in arbitrary command execution on the underlying system. Successful exploitation allows remote code execution with the privileges of the affected application.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.012 (68.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 68.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6721: held from 0.014 to 0.012.

EPSS over last 30 days · oldest: 0.014 · newest: 0.012 · change: -0.003

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6721?
CVE-2026-6721 is a critical-severity vulnerability in IBM Concert, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-09-23.
How severe is CVE-2026-6721?
Critical severity. CVSS v3 base score is 9.8 out of 10.