Question 1

What is the EOL Risk Score for IBM z/OS 2.5?

Accepted Answer

IBM z/OS 2.5 has an EOL Risk Score™ of 25 out of 100, placing it in the Low risk band. The score is calculated from four factors: EOL Recency (15/40), Attack Surface (10/30), CISA KEV Exposure (0/20), and Extended Support Availability (0/10).

Question 2

Is IBM z/OS 2.5 still supported?

Accepted Answer

IBM z/OS 2.5 is currently supported. End of life is scheduled for September 30, 2026. Plan your migration before that date to avoid security risk.

Question 3

When does IBM z/OS 2.5 reach end of life?

Accepted Answer

IBM z/OS 2.5 reached (or will reach) end of life on September 30, 2026. After this date, no security patches or bug fixes are issued by the vendor.

Question 4

What are the security risks of running IBM z/OS 2.5 after end of life?

Accepted Answer

After end of life, IBM z/OS 2.5 no longer receives security patches. Any newly discovered CVEs remain unpatched indefinitely. Organizations running EOL software also face compliance violations under SOC 2, PCI DSS, HIPAA, and ISO 27001, which require use of supported software versions.