CVE-2026-21656

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.39% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 32.3% of scored records. A rank, not a probability.

NVD base score

8.8 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-02-27 08:47Z6 MO AGO

Last updated

2026-03-06 18:42Z6 MO AGO

Reserved

2026-01-02

Assigning CNA

jci

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-94Improper Control of Generation of Code ('Code Injection')Base

Data version

5.2

Document digest

e90f8af30ab7c32e8af1349ba3c090b02d60a0af6e51e59a7ccaed5070160c56

• www.cisa.govhttps://www.cisa.gov/news-events/ics-advisories/icsa-26-057-01
• www.johnsoncontrols.comhttps://www.johnsoncontrols.com/trust-center/cybersecurity/security-advisories