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

> Attackers can cause denial of service in Keycloak by exhausting JWT token cache memory if long-expiration tokens are used.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Mar 2025
- **Updated:** 21 Sep 2026
- **Also known as:** ECHO-8712-b79a-9acd, GHSA-2935-2wfm-hhpv

## What is CVE-2025-2559?

CVE-2025-2559 is a medium-severity denial of service vulnerability in Red Hat Build of Keycloak, published on 25 Mar 2025. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2025-2559?

2 open source packages ship an affected version, including org.keycloak:keycloak-services.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-services` | Maven | All versions to 26.1.4 | None |
| `org.keycloak:keycloak-services` | Maven | All versions to 26.1.4 | None |

## How do I fix CVE-2025-2559?

Apply the vendor's patch.

## Is CVE-2025-2559 being exploited?

There is no known exploitation of CVE-2025-2559 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-2559 and fix it if it is affected.

What it is: CVE-2025-2559 is a medium-severity denial of service vulnerability in Red Hat Build of Keycloak, published on 25 Mar 2025. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-2559 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-services (Maven): affected all versions up to 26.1.4; no fix listed
- org.keycloak:keycloak-services (Maven): affected all versions up to 26.1.4; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-2559/ (Markdown: https://insights.sbomify.com/CVE-2025-2559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-2559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-2559
- OSV: https://osv.dev/vulnerability/CVE-2025-2559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-2559/
Summaries are generated and may contain mistakes; the official description above is the record.