How severe is CVE-2021-36222?

CVE-2021-36222 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-36222 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36222?

CVE-2021-36222 primarily affects Mit Kerberos 5. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-36222?

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

When was CVE-2021-36222 published?

CVE-2021-36222 was published on 2021-07-22 and last updated on 2026-06-17.

CVE-2021-36222

CVE-2021-36222 is a high-severity vulnerability in Mit Kerberos 5 with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 10% places it in the 95th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 10% (95th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Mit Kerberos 5
Published: 2021-07-22
Last modified: 2026-06-17

Description

ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.

Frequently asked questions

What is CVE-2021-36222?: ec_verify in kdc/kdc_preauth_ec.c in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.18.4 and 1.19.x before 1.19.2 allows remote attackers to cause a NULL pointer dereference and daemon crash. This occurs because a return value is not properly managed in a certain situation.
How severe is CVE-2021-36222?: CVE-2021-36222 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-36222 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (95th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36222?: CVE-2021-36222 primarily affects Mit Kerberos 5. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-36222?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-36222 published?: CVE-2021-36222 was published on 2021-07-22 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:*
cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:windows:*:*
cpe:2.3:a:netapp:oncommand_insight:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:oncommand_workflow_automation:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:snapcenter:-:*:*:*:*:*:*:*
cpe:2.3:a:oracle:mysql_server:*:*:*:*:*:*:*:*

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Other CWE-476 (NULL Pointer Dereference) vulnerabilities

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CVE-2026-31657 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by…
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Browse all CWE-476 (NULL Pointer Dereference) vulnerabilities →