How severe is CVE-2021-20538?

CVE-2021-20538 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-20538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20538?

CVE-2021-20538 primarily affects Ibm Cloud Pak For Security. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20538?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-20538 published?

CVE-2021-20538 was published on 2021-05-10 and last updated on 2026-06-17.

CVE-2021-20538

CVE-2021-20538 is a critical-severity vulnerability in Ibm Cloud Pak For Security with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Ibm Cloud Pak For Security
Published: 2021-05-10
Last modified: 2026-06-17

Description

IBM Cloud Pak for Security (CP4S) 1.5.0.0 and 1.5.0.1 could allow a user to obtain sensitive information or perform actions they should not have access to due to incorrect authorization mechanisms. IBM X-Force ID: 198919.

Frequently asked questions

What is CVE-2021-20538?: IBM Cloud Pak for Security (CP4S) 1.5.0.0 and 1.5.0.1 could allow a user to obtain sensitive information or perform actions they should not have access to due to incorrect authorization mechanisms. IBM X-Force ID: 198919.
How severe is CVE-2021-20538?: CVE-2021-20538 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-20538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20538?: CVE-2021-20538 primarily affects Ibm Cloud Pak For Security. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20538?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-20538 published?: CVE-2021-20538 was published on 2021-05-10 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ibm:cloud_pak_for_security:1.5.0.0:*:*:*:*:*:*:*
cpe:2.3:a:ibm:cloud_pak_for_security:1.5.0.1:*:*:*:*:*:*:*

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