What is CVE-2021-31009?

CVE-2021-31009 is a critical-severity vulnerability in Apple iOS And Ipados. CVSS score: 9.8/10. Published 2021-08-24.

How severe is CVE-2021-31009?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Apple iOS And Ipados

CVE-2021-31009

Multiple issues were addressed by removing HDF5. This issue is fixed in iOS 15.2 and iPadOS 15.2, macOS Monterey 12.1. Multiple issues in HDF5.

Published 2021-08-24 · last modified 2026-06-17.

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 (67.0th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Apple iOS And Ipados — versions unspecified
Apple Ipados
Apple Iphone OS
Apple macOS — versions unspecified

References

Frequently asked questions

What is CVE-2021-31009?: CVE-2021-31009 is a critical-severity vulnerability in Apple iOS And Ipados. CVSS score: 9.8/10. Published 2021-08-24.
How severe is CVE-2021-31009?: Critical severity. CVSS v3 base score is 9.8 out of 10.