CVE-2023-1664Network attack vector

Unauthenticated application access via missing truststore validation

Published May 26, 2023 · Updated Jan 15, 2025

Improper certificate validation in Red Hat build of Keycloak allows remote attackers to gain application access with a chosen certificate. The X.509 client certificate authenticator accepts the attacker-selected certificate when revalidation is enabled but the configured truststore is absent or unusable. Exploitation requires direct access that bypasses certificate validation at the reverse proxy and can expose or alter data in consumer applications.

CVSS severity6.5
Medium
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper certificate validation in Red Hat build of Keycloak allows remote attackers to gain application access with a chosen certificate. The X.509 client certificate authenticator accepts the attacker-selected certificate when revalidation is enabled but the configured truststore is absent or unusable. Exploitation requires direct access that bypasses certificate validation at the reverse proxy and can expose or alter data in consumer applications.

The record

CVE
CVE-2023-1664
Published
May 26, 2023
Updated
Jan 15, 2025
Vendor
Red Hat
Product
Red Hat build of Keycloak
Classifications
CWE-295
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=NA

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Red Hat · Red Hat build of Keycloakversion=NA

Published CVSS scores

6.5Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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