How severe is CVE-2021-22138?

CVE-2021-22138 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-22138 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22138?

CVE-2021-22138 affects Elastic Logstash. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-22138?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22138 published?

CVE-2021-22138 was published on 2021-05-13 and last updated on 2026-06-17.

CVE-2021-22138

CVE-2021-22138 is a low-severity vulnerability in Elastic Logstash with a CVSS 3.x base score of 3.7. 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-295.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
CVSS v2: 4.3
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Elastic Logstash
Published: 2021-05-13
Last modified: 2026-06-17

Description

In Logstash versions after 6.4.0 and before 6.8.15 and 7.12.0 a TLS certificate validation flaw was found in the monitoring feature. When specifying a trusted server CA certificate Logstash would not properly verify the certificate returned by the monitoring server. This could result in a man in the middle style attack against the Logstash monitoring data.

Frequently asked questions

What is CVE-2021-22138?: In Logstash versions after 6.4.0 and before 6.8.15 and 7.12.0 a TLS certificate validation flaw was found in the monitoring feature. When specifying a trusted server CA certificate Logstash would not properly verify the certificate returned by the monitoring server. This could result in a man in the middle style attack against the Logstash monitoring data.
How severe is CVE-2021-22138?: CVE-2021-22138 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-22138 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22138?: CVE-2021-22138 affects Elastic Logstash. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-22138?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22138 published?: CVE-2021-22138 was published on 2021-05-13 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:elastic:logstash:*:*:*:*:*:*:*:*

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