NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
☕
☕ Maven
Not in CISA KEV
LOW severity

CVE-2026-4874 — keycloak-services

LOWFix: keycloak/keycloak#49682

CVE-2026-4874 is a low-severity (CVSS 3.1) Server-Side Request Forgery (SSRF) vulnerability in org.keycloak:keycloak-services. A fix is available for org.keycloak:keycloak-services — see the affected versions and patch details below.

Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation

Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-4874.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk
0.00%0.28%0.57%0.85%0.0%0.4%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected
☕org.keycloak:keycloak-services☕org.keycloak:keycloak-services

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the client_session_host parameter during refresh token requests. This occurs when a Keycloak client is configured to use the backchannel.logout.url with the application.session.host placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.keycloak:keycloak-services≥ 26.5.0&&< 26.6.326.6.3org.keycloak:keycloak-services:26.6.3
☕Mavenorg.keycloak:keycloak-servicesall versions26.4.13org.keycloak:keycloak-services:26.4.13

Affected Products

4 products · 4 configurations
Application
build of keycloakredhat
all
Application
jboss enterprise application platformredhat
1 version
8.0.0
Application
jboss enterprise application platform expansion packredhat
all
Application
single sign-onredhat
1 version
7.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.keycloak:keycloak-services, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update org.keycloak:keycloak-services to 26.6.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-4874 is resolved across your whole dependency graph.

  3. Workarounds

    Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow

This flaw allows an authenticated attacker to perform Server-Side Request Forgery (SSRF) by manipulating the `client_session_host` parameter during refresh token requests. This vulnerability is exploitable when a Keycloak client is configured to use the `backchannel.logout.url` with the `application.session.host`…

Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for CVE-2026-4874 (CC BY 4.0)
ProductFixed inAdvisory
Red Hat build of Keycloak 26.4rhbk/keycloak-operator-bundle:26.4.13-1RHSA-2026:30050
Red Hat build of Keycloak 26.4.13rhbk/keycloak-rhel9RHSA-2026:30049
Red Hat build of Keycloak 26.6rhbk/keycloak-operator-bundle:26.6.3-3RHSA-2026:25097
Red Hat build of Keycloak 26.6.3rhbk/keycloak-rhel9RHSA-2026:25098

Frequently Asked Questions

A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the `client_session_host` parameter during refresh token requests. This occurs when a Keycloak client is configured to use the `backchannel.logout.url` with the `application.session.host` placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.
O3 Security · Impact-Aware SCA

Is CVE-2026-4874 in your dependencies?

Find it across Maven, including transitive dependencies.

Scan my dependencies How O3 SCA works
CVE-2026-4874: keycloak-services SSRF — Fixed in 26.6.3