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» 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.
NVD Status： Modified ，CVE State: published
Threat Intelligence & Risk Assessment for CVE-2020-1758
Conclusion & alert: CVE-2020-1758 is rated Moderate Risk (41.1/100) : CVSS Medium severity, with medium exploitation likelihood (EPSS 0.91%).Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2020-1758
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
#
Date
Old EPSS score
New EPSS score
Delta (New - Old)
1
2026-06-15
0.25%
0.91%
+0.65%
2
2025-11-21
0.18%
0.25%
+0.07%
3
2025-11-18
—
0.18%
—
Full EPSS history
(11 records total)
Common vulnerability scoring system (CVSS) metrics for CVE-2020-1758
CVSS metrics for this CVE.
Base score
Version
Severity
Vector
Exploitability
Impact
Score source
5.3
3.1
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
1.6
3.6
[email protected]
5.9
3.1
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
2.2
3.6
[email protected]
4.3
2.0
MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N
Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
8.6
2.9
[email protected]
Weakness enumeration for CVE-2020-1758
GitHub Security Advisory for CVE-2020-1758
GHSA-c597-f74m-jgc2 · Severity: medium · Ecosystem: maven
— Improper Certificate Validation and Improper Validation of Certificate with Host Mismatch in Keycloak
OS Trackers for CVE-2020-1758
Affected software / configurations for CVE-2020-1758
Vendor
Product
Version
Raw CPE
redhat
keycloak
< 10.0.0
cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*
redhat
openstack
10
cpe:2.3:a:redhat:openstack:10:*:*:*:*:*:*:*
References for CVE-2020-1758
cvelogic
Threat Intelligence