CVE-2023-6563

Keycloak: offline session token dos

Published: Dec 14, 2023Updated: Sep 22, 2026 Sources: CVE List NVD GHSACWE-770

7.7HIGH

Description

An unconstrained memory consumption vulnerability was discovered in Keycloak. It can be triggered in environments which have millions of offline tokens (> 500,000 users with each having at least 2 saved sessions). If an attacker creates two or more user sessions and then open the "consents" tab of the admin User Interface, the UI attempts to load a huge number of offline client sessions leading to excessive memory and CPU consumption which could potentially crash the entire system.

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:LPrivileges Required

Low

UI:NUser Interaction

None

Scope

S:CScope

Changed

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

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Weaknesses

CWE-770

Affected Products

Red Hat

commercial·USaka redhat

keycloakOn-prem

Operating Systems / linux-distro

single sign-onOn-prem

Operating Systems / linux-distro

openshift container platformOn-prem

Operating Systems / linux-distro

openshift container platform for powerOn-prem

Operating Systems / linux-distro

openshift container platform for ibm linuxoneOn-prem

Operating Systems / linux-distro

Red Hat Single Sign-On 7.6 for RHEL 7On-premSecurity Product

Security Products / identity-access-mgmt

Red Hat Single Sign-On 7.6 for RHEL 8On-premSecurity Product

Security Products / identity-access-mgmt

Red Hat Single Sign-On 7.6 for RHEL 9On-premSecurity Product

Security Products / identity-access-mgmt

Maven

package-ecosystem

org.keycloak:keycloak-model-jpa

OSS Libraries

and 3 more affected products View all →

Exploitability

1 exploit source identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details

Official Patch Available

Workaround Available

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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique

Impact

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References

https://access.redhat.com/errata/RHSA-2023:7854

access.redhat.com

https://access.redhat.com/errata/RHSA-2023:7855

access.redhat.com

https://access.redhat.com/errata/RHSA-2023:7856

access.redhat.com

and 9 more references View all →

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