CVE-2023-1664

mediumpriority · track · 26EPSS 0.004 · 37 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.43% (37th) EPSS

CVSS 6.5 · medium

Is it mine?

17 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A flaw was found in Keycloak. This flaw depends on a non-default configuration "Revalidate Client Certificate" to be enabled and the reverse proxy is not validating the certificate before Keycloak. Using this method an attacker may choose the certificate which will be validated by the server. If this happens and the KC_SPI_TRUSTSTORE_FILE_FILE variable is missing/misconfigured, any trustfile may be accepted with the logging information of "Cannot validate client certificate trust: Truststore not available". This may not impact availability as the attacker would have no access to the server, but consumer applications Integrity or Confidentiality may be impacted considering a possible access to them. Considering the environment is correctly set to use "Revalidate Client Certificate" this flaw is avoidable.

cvss

Technical severity, 0–10. One row per scoring source.

6.5

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 3.9 · impact 2.5

v3.16.5mediumAV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · ENISA EU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondaryexploitability 3.9 · impact 2.5

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Nsecondary · OSV

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-295USCWE-295US

affected products (17)

Products and version ranges known to be affected.

Open Source Keycloakall versionscert_bundDEcpe:/a:keycloak:keycloak:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Single Sign On 7all versionscert_bundDEcpe:/a:redhat:single_sign_on:7.x
n/a KeyCloak≤ NAenisa_euvdEU
Red Hat Inc. Keycloakall versionsfstec_bduRU
Red Hat Inc. Keycloak≤ 22.0.1fstec_bduRU
Red Hat Inc. Migration Toolkit for Runtimesall versionsfstec_bduRU
Red Hat Inc. Red Hat Enterprise Linux≤ 8 based Middleware Containersfstec_bduRU
Red Hat Inc. Red Hat JBoss A-MQ≤ 7fstec_bduRU
Red Hat Inc. Red Hat Single Sign-On≤ 7fstec_bduRU
Red Hat Inc. Red Hat Single Sign-On≤ 7.6fstec_bduRU
redhat build of quarkusall versionsnvdUScpe:2.3:a:redhat:build_of_quarkus:*:*:*:*:*:*:*:*
redhat jboss a-mq= 7nvdUScpe:2.3:a:redhat:jboss_a-mq:*:*:*:*:*:*:*:*
redhat keycloakall versionsnvdUScpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*
redhat migration toolkit for runtimesall versionsnvdUScpe:2.3:a:redhat:migration_toolkit_for_runtimes:*:*:*:*:*:*:*:*
redhat single sign-on= 7.0nvdUScpe:2.3:a:redhat:single_sign-on:*:*:*:*:*:*:*:*
Maven org.keycloak:keycloak-core< 21.1.2osvUSpkg:maven/org.keycloak/keycloak-core

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-0764Keycloak: Schwachstelle ermöglicht Umgehen von SicherheitsvorkehrungenDeutsch2023-03-27csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Keycloak und Red Hat Single Sign On ausnutzen, um Sicherheitsvorkehrungen zu umgehen.
GHSA-5cc8-pgp5-7mpmKeycloak Untrusted Certificate Validation vulnerability2023-06-30ghsa · osvUS
A flaw was found in keycloak-core. This flaw considers the scenario when using X509 Client Certificate Authenticatior with the option "Revalidate Client Certificate". A user may be able to choose, if directly connect to keycloak (not passing via reverse proxy) a specific certificate. If there's a configuration error in KC_SPI_TRUSTSTORE_FILE_FILE the authenticator allows even with the "Cannot validate client certificate trust: Truststore not available" message as there's no certificate to trust against.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd osv NVD CVE.org MITRE

published 2023-05-26modified 2026-06-17

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+1889 more

references (6)

External citations — patches, advisories, analysis.

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