Skip to main content

Keycloak CVE-2026-16442

| EUVDEUVD-2026-53395 CRITICAL
Origin Validation Error (CWE-346)
2026-08-05 redhat GHSA-vj6m-hv26-qx79
9.8
CVSS 3.1 · NVD
Share

Severity by source

Vendor (redhat) PRIMARY
HIGH
qualitative
NVD
9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
9.1 CRITICAL

Network-reachable endpoint with no privileges on Keycloak yields AV:N/PR:N; account takeover gives C:H/I:H, but there is no direct availability impact so A:N (vs vendor A:H).

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Red Hat
7.4 HIGH
qualitative

Primary rating from Vendor (redhat).

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

6
Analysis Updated
Aug 10, 2026 - 19:29 vuln.today
v2 (cvss_changed)
Re-analysis Queued
Aug 10, 2026 - 19:22 vuln.today
cvss_changed
Severity Changed
Aug 10, 2026 - 19:22 NVD
HIGH CRITICAL
CVSS changed
Aug 10, 2026 - 19:22 NVD
7.4 (HIGH) 9.8 (CRITICAL)
Analysis Generated
Aug 05, 2026 - 15:47 vuln.today
CVE Published
Aug 05, 2026 - 15:00 cve.org
HIGH 7.4

DescriptionNVD

A flaw was found in the SAML broker component of Keycloak, which is used to manage identity federation and user authentication. The issue occurs because the IdP-initiated Single Sign-On endpoint fails to check if a provider is restricted to account linking only. This allows an attacker with control over a linked upstream identity to bypass login restrictions and gain full access to a local user account.

AnalysisAI

Account takeover in Keycloak (Red Hat build of Keycloak, Red Hat Single Sign-On 7) arises because the IdP-initiated SAML SSO endpoint does not verify whether an upstream identity provider is restricted to account-linking-only mode. An attacker who controls a linked upstream identity can drive that endpoint to complete a full login rather than a mere link operation, seizing complete access to the corresponding local user account. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Control a linked upstream SAML identity
Delivery
Invoke IdP-initiated SSO endpoint
Exploit
Endpoint skips linking-only check
Execution
Full session issued as victim
Impact
Take over local account

Vulnerability AssessmentAI

Exploitation Exploitation requires that the Keycloak deployment uses SAML identity brokering with at least one upstream provider configured as 'account linking only', and that the attacker controls an upstream identity already linked to a target local account; the attack is then delivered through the IdP-initiated SAML SSO endpoint. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment Signals here are mixed and warrant careful interpretation rather than reflexive escalation. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker registers or compromises an identity at an upstream IdP that a victim has linked to their Keycloak account under an account-linking-only provider. The attacker then invokes the SAML broker's IdP-initiated SSO endpoint with that upstream identity; because the endpoint never checks the linking-only restriction, Keycloak establishes a full authenticated session as the victim's local user. …
Remediation Apply the vendor-released patches: update the Red Hat build of Keycloak to 26.4 (package 26.4-22 or 26.4.14-1) or 26.6 (package 26.6-11 or 26.6.5-1), and apply the corresponding RHSA errata for the affected products (https://access.redhat.com/errata/RHSA-2026:50846, RHSA-2026:50847, RHSA-2026:50848, and RHSA-2026:50849). … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours, identify and document all Keycloak and Red Hat Single Sign-On 7 instances in your environment, particularly those configured with external SAML identity providers and supporting administrative access. …

Sign in for detailed remediation steps and compensating controls.

Threat intelligence, references, and detailed analysis are available after sign-in.

CVE-2026-18963 CRITICAL
9.1 Aug 18

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

CVE-2026-16443 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-2026-9800 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

CVE-2026-7504 HIGH
8.1 May 19

Open redirect in Red Hat build of Keycloak permits remote attackers to send victims to attacker-controlled hosts by abus

CVE-2026-9087 HIGH
8.1 May 20

Identity linking bypass in Red Hat build of Keycloak allows an attacker controlling a second account on the same upstrea

Vendor StatusVendor

Share

CVE-2026-16442 vulnerability details – vuln.today

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