What is CVE-2021-38991?

CVE-2021-38991 is a high-severity vulnerability in IBM Aix. CVSS score: 7.8/10. Published 2022-01-11.

How severe is CVE-2021-38991?

High severity. CVSS v3 base score is 7.8 out of 10.

Vulnerability in IBM Aix

CVE-2021-38991

IBM AIX 7.0, 7.1, 7.2, and VIOS 3.1 could allow a non-privileged local user to exploit a vulnerability in the lscore command which could lead to code execution. IBM X-Force ID: 212953.

Published 2022-01-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (17.6th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

IBM Aix — versions 7.0, 7.2, 7.3
IBM Vios — versions 3.1

References

www.ibm.com/support/pages/node/6538952 (Patch, Vendor Advisory)
exchange.xforce.ibmcloud.com/vulnerabilities/212953 (VDB Entry, vdb-entry, Vendor Advisory)

Frequently asked questions

What is CVE-2021-38991?: CVE-2021-38991 is a high-severity vulnerability in IBM Aix. CVSS score: 7.8/10. Published 2022-01-11.
How severe is CVE-2021-38991?: High severity. CVSS v3 base score is 7.8 out of 10.