CVE-2025-2559 | Org.keycloak/keycloak-services: jwt token cache exhaustion leading to denial of service (dos) in keycloak

A flaw was found in Keycloak. When the configuration uses JWT tokens for authentication, the tokens are cached until expiration. If a client uses JWT tokens with an excessively long expiration time, for example, 24 or 48 hours, the cache can grow indefinitely, leading to an OutOfMemoryError. This issue could result in a denial of service condition, preventing legitimate users from accessing the system.

Published: 2025-03-25 Last update: 2026-05-06 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-2559 is rated Low Risk (20.3/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2025-2559

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 2026-05-03 0.11% 0.01% -0.10%
2 2026-02-18 0.39% 0.11% -0.27%
3 2026-01-19 — 0.39% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-2559

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H 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:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.2 3.6 [email protected]

Weakness enumeration for CVE-2025-2559

GitHub Security Advisory for CVE-2025-2559

GHSA-2935-2wfm-hhpv · Severity: medium · Ecosystem: maven — Keycloak Denial of Service (DoS) Vulnerability via JWT Token Cache

OS Trackers for CVE-2025-2559

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-2559

Affected software / configurations for CVE-2025-2559

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-2559

cvelogic Threat Intelligence