Skip to main content

Red Hat Build Of Keycloak EUVDEUVD-2026-18210

| CVE-2026-4325 MEDIUM
Improper Isolation or Compartmentalization (CWE-653)
2026-04-02 redhat GHSA-rx66-hj7g-28h7
5.3
CVSS 3.1 · Vendor: redhat
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V15 - Secure Coding and Architecture Component isolation
Impact

While the CVSS score of 5.3 appears moderate, the attack vector (network-accessible), integrity impact (high), and authentication bypass classification indicate meaningful real-world risk. The high attack complexity (AC:H) and required user interaction (UI:R) significantly reduce practical exploitability, suggesting this is not a trivial remote attack. The CVSS score reflects these constraints accurately. Exploitation requires an attacker to craft a specific request to delete legitimate single-use entries, then socially engineer or wait for a user to attempt legitimate token usage, making this a multi-step attack. The integrity impact (I:H) is significant because successful exploitation directly compromises account security through token replay. No KEV confirmation or public POC availability was noted in the provided intelligence, suggesting this remains a lower-priority patch candidate compared to unauthenticated, low-complexity vulnerabilities, though the authentication bypass classification warrants timely remediation.

Exploit ScenarioDerived

An attacker discovers or infers the namespace structure of Keycloak's SingleUseObjectProvider and crafts a request to delete password reset tokens for a target user. When the victim initiates a legitimate password reset workflow, they receive a reset link, but when they attempt to use it, the token has already been deleted by the attacker, forcing them to request a new one. Alternatively, the attacker could delete tokens preemptively and then exploit a race condition or timing window to insert their own password reset request, potentially gaining account access. The high attack complexity and required user interaction suggest this attack is not trivial but is feasible against high-value targets.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Apr 02, 2026

Keycloak's SingleUseObjectProvider lacks proper type and namespace isolation, allowing unauthenticated remote attackers with user interaction to delete arbitrary single-use entries and replay consumed action tokens such as password reset links, leading to account compromise. The vulnerability requires user interaction (UI:R) and high attack complexity (AC:H), resulting in a CVSS score of 5.3. No public exploit code or active exploitation has been confirmed at time of analysis.

RemediationAI

Organizations running Red Hat Build of Keycloak should apply the vendor-released patch corresponding to their deployed version as soon as practical. Consult Red Hat's official security advisory at https://access.redhat.com/security/cve/CVE-2026-4325 for specific patched version numbers and upgrade instructions. Interim mitigations should focus on restricting access to password reset and account recovery flows to authenticated, trusted networks if operationally feasible, and monitoring for unusual token consumption patterns. Organizations should prioritize patching authentication-critical systems first, given the potential for account compromise through token replay attacks.

Affected Packages

maven org.keycloak:keycloak-services fix: 26.5.7

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in maven

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Keycloak's SingleUseObjectProvider is a global key-value store mechanism responsible for managing single-use tokens and action tokens, including password reset and email verification links. The vulnerability stems from improper isolation of token types and namespaces (CWE-653: Unsupported Feature in Generator), allowing attackers to manipulate the store without proper access controls or validation. This design flaw enables an attacker to enumerate and delete entries belonging to other users or sessions, effectively invalidating the single-use constraint that these tokens are designed to enforce. The affected component is present in Red Hat Build of Keycloak across multiple versions as indicated by the wildcard CPE specification.

Know when Red Hat Build Of Keycloak gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (redhat) PRIMARY 5.3 MEDIUM
AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Red Hat 5.3 MEDIUM

Primary rating from Vendor (redhat).

CVSS VectorVendor: redhat

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

Lifecycle Timeline

2
Patch released
Apr 04, 2026 - 08:30 nvd
Patch available
CVE Published
Apr 02, 2026 - 12:44 nvd
MEDIUM 5.3

DescriptionCVE.org

A flaw was found in Keycloak. The SingleUseObjectProvider, a global key-value store, lacks proper type and namespace isolation. This vulnerability allows an attacker to delete arbitrary single-use entries, which can enable the replay of consumed action tokens, such as password reset links. This could lead to unauthorized access or account compromise.

Blast Radius

ecosystem impact
† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth
  • 54 maven packages depend on org.keycloak:keycloak-services (26 direct, 28 indirect)

Ecosystem-wide dependent count for version 26.5.7.

Threat Intelligence Overview

EPSS Score
0.0%
Top 90% exploitable
Data Quality
6 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment Vendor VulDB

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation
None
System Exposure· derived
Open
Automatable
No
Human Impact· derived
Medium
Technical Impact
Partial

Priority Score

26
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +26
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

Affected Products (CPE)CVE.org

cpe:2.3:a:red_hat:red_hat_build_of_keycloak:*:*:*:*:*:*:*:*

Related Vulnerabilities in Keycloak Authentication and Authorization Bypass

View all 5
CVE-2026-18963 CRITICAL POC
9.1 Aug 18

Account takeover in Red Hat Build of Keycloak allows an unauthenticated attacker to abuse the reset-credentials flow in

CVE-2026-16442 CRITICAL
9.8 Aug 05

Account takeover in Keycloak (Red Hat build of Keycloak, Red Hat Single Sign-On 7) arises because the IdP-initiated SAML

CVE-2026-16443 CRITICAL
9.1 Aug 05

Authentication bypass in Red Hat Build of Keycloak (and Red Hat Single Sign-On 7) lets an unauthenticated attacker forge

CVE-2026-15572 HIGH
8.8 Aug 05

Privilege escalation in Red Hat Build of Keycloak's Dynamic Client Registration (DCR) grants an attacker with low-privil

CVE-2026-93569 HIGH
8.2 Sep 18

Mismatched handling of the HTTP/1 absolute-form request authority in Red Hat build of Quarkus and other affected Red Hat

CVE-2026-9800 HIGH
8.1 Jun 25

Authorization bypass in the Keycloak Policy Enforcer allows any authenticated user to circumvent all enforced access con

CVE-2026-15573 HIGH
8.1 Aug 05

URI normalization bypass in Keycloak's Authorization Services PathMatcher allows authenticated low-privilege users to re

CVE-2026-16102 HIGH
8.1 Aug 05

Privilege escalation in Keycloak's Dynamic Client Registration (DCR) component allows attackers with standard user accou

CVE-2026-18214 HIGH
8.1 Jul 31

Token exchange in Keycloak bypasses Google Workspace domain allowlist restrictions, enabling any valid Google account ho

CVE-2026-11800 HIGH
8.1 Jun 25

Signature-verification bypass in Keycloak (and Red Hat's Keycloak-based products such as Red Hat Single Sign-On 7 and Re

CVE-2026-18215 HIGH
8.1 Jul 31

Tenant-restriction bypass in Keycloak's Microsoft identity provider integration allows attackers holding any valid Micro

CVE-2026-18967 HIGH
8.1 Aug 06

Session hijacking via SAML assertion replay in Keycloak's SAML broker component allows adjacent-network attackers to aut

Vendor StatusVendor

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy