Unauthenticated remote OS command injection in an IBM enterprise product (Concert) allowing RCE with app privileges; broad enterprise impact and high CVSS 9.8 merits org‑wide alert.
CVE-2026-6721
Unauthenticated OS command injection in IBM Concert allows remote code execution.
Is CVE-2026-6721 being exploited?
Not confirmed. CVE-2026-6721 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.2% probability of exploitation in the next 30 days.
How severe is CVE-2026-6721?
CVE-2026-6721 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-6721?
Yes. A fix has been recorded for CVE-2026-6721. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-6721 affect?
CVE-2026-6721 affects IBM Concert 1.0.0 - 3.0.0. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-6721?
Isolate/segregate Concert, block access, deploy WAF rules, apply vendor patch when released
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote command injection (CWE-78) yields remote code execution as the application user, enabling system compromise and lateral movement.
Immediate action required
- affected>= 1.0.0 and <= 3.0.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
cisa ssvc
- exploitation
- none
- automatable
- yes
- technical impact
- total
Assessed by CISA 24 Sept 2026 (SSVC 2.0.3).
timeline
- 23 Sept 2026Published
- 24 Sept 2026CISA SSVC assessment: exploitation none · same day later
- 24 Sept 2026Analysed by vulneraibility.com · same day later
- 25 Sept 2026CVE record last updated · 1 day later
- Patchibm.com /support/pages/node/7288830
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.