CVE-2026-4874 | Org.keycloak.protocol.oidc.grants: org.keycloak.services.managers: keycloak: server-side request forgery via oidc token endpoint manipulation

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.

Published: 2026-03-26 Last update: 2026-06-26 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-4874 is rated Low Risk (18.3/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.25%). Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

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-2026-4874

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 2026-06-15 0.03% 0.25% +0.23%
2 2026-03-26 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-4874

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 1.4 [email protected]
3.1 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N 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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 1.6 1.4 [email protected]

Weakness enumeration for CVE-2026-4874

GitHub Security Advisory for CVE-2026-4874

GHSA-22rm-wp4x-v5cx · Severity: low · Ecosystem: maven — Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation

OS Trackers for CVE-2026-4874

vendor priority summary link
redhat low — https://access.redhat.com/security/cve/CVE-2026-4874

Affected software / configurations for CVE-2026-4874

Vendor Product Version Raw CPE
redhat build_of_keycloak — cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*
redhat jboss_enterprise_application_platform 8.0.0 cpe:2.3:a:redhat:jboss_enterprise_application_platform:8.0.0:*:*:*:*:*:*:*
redhat jboss_enterprise_application_platform_expansion_pack — cpe:2.3:a:redhat:jboss_enterprise_application_platform_expansion_pack:-:*:*:*:*:*:*:*
redhat single_sign-on 7.0 cpe:2.3:a:redhat:single_sign-on:7.0:*:*:*:*:*:*:*

References for CVE-2026-4874

cvelogic Threat Intelligence