How severe is CVE-2020-1758?

CVE-2020-1758 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-1758 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-1758?

CVE-2020-1758 primarily affects Redhat Keycloak. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-1758?

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

When was CVE-2020-1758 published?

CVE-2020-1758 was published on 2020-05-15 and last updated on 2026-06-17.

CVE-2020-1758

CVE-2020-1758 is a medium-severity vulnerability in Redhat Keycloak with a CVSS 3.x base score of 5.3. 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: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-295
Affected product: Redhat Keycloak
Published: 2020-05-15
Last modified: 2026-06-17

Description

A flaw was found in Keycloak in versions before 10.0.0, where it does not perform the TLS hostname verification while sending emails using the SMTP server. This flaw allows an attacker to perform a man-in-the-middle (MITM) attack.

Frequently asked questions

What is CVE-2020-1758?: A flaw was found in Keycloak in versions before 10.0.0, where it does not perform the TLS hostname verification while sending emails using the SMTP server. This flaw allows an attacker to perform a man-in-the-middle (MITM) attack.
How severe is CVE-2020-1758?: CVE-2020-1758 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-1758 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-1758?: CVE-2020-1758 primarily affects Redhat Keycloak. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-1758?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-1758 published?: CVE-2020-1758 was published on 2020-05-15 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:*

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