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Vulnerability Details :

CVE-2026-7571

Summary
Assigner-redhat
Assigner Org ID-53f830b8-0a3f-465b-8143-3b8a9948e749
Published At-19 May, 2026 | 11:01
Updated At-19 May, 2026 | 12:00
Rejected At-
Credits

Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

Vendors
-
Not available
Products
-
Metrics (CVSS)
VersionBase scoreBase severityVector
Weaknesses
Attack Patterns
Solution/Workaround
References
HyperlinkResource Type
EPSS History
Score
Latest Score
-
N/A
No data available for selected date range
Percentile
Latest Percentile
-
N/A
No data available for selected date range
Stakeholder-Specific Vulnerability Categorization (SSVC)
▼Common Vulnerabilities and Exposures (CVE)
cve.org
Assigner:redhat
Assigner Org ID:53f830b8-0a3f-465b-8143-3b8a9948e749
Published At:19 May, 2026 | 11:01
Updated At:19 May, 2026 | 12:00
Rejected At:
▼CVE Numbering Authority (CNA)
Keycloak: keycloak: access token disclosure and implicit flow bypass via forged client data

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

Affected Products
Vendor
Red Hat, Inc.Red Hat
Product
Red Hat Build of Keycloak
Collection URL
https://access.redhat.com/downloads/content/package-browser/
Package Name
rhbk/keycloak-rhel9-operator
CPEs
  • cpe:/a:redhat:build_keycloak:
Default Status
affected
Problem Types
TypeCWE IDDescription
CWECWE-472External Control of Assumed-Immutable Web Parameter
Type: CWE
CWE ID: CWE-472
Description: External Control of Assumed-Immutable Web Parameter
Metrics
VersionBase scoreBase severityVector
3.17.1HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Version: 3.1
Base score: 7.1
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Metrics Other Info
Red Hat severity rating
value:
Moderate
namespace:
https://access.redhat.com/security/updates/classification/
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds

To mitigate this issue, restrict network access to the Keycloak authentication endpoint to trusted clients and networks. Implement firewall rules to control inbound connections to the Keycloak service ports, thereby reducing the attack surface and limiting who can initiate authentication flows and potentially exploit the implicit flow bypass. If the Keycloak service is reloaded or restarted, ensure these network restrictions remain in effect.

Exploits
Credits
Red Hat would like to thank Evan Hendra for reporting this issue.
Timeline
EventDate
Reported to Red Hat.2026-04-30 22:22:41
Made public.2026-05-19 10:50:49
Event: Reported to Red Hat.
Date: 2026-04-30 22:22:41
Event: Made public.
Date: 2026-05-19 10:50:49
Replaced By
Rejected Reason
References
HyperlinkResource
https://access.redhat.com/security/cve/CVE-2026-7571
vdb-entry
x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2464263
issue-tracking
x_refsource_REDHAT
Hyperlink: https://access.redhat.com/security/cve/CVE-2026-7571
Resource:
vdb-entry
x_refsource_REDHAT
Hyperlink: https://bugzilla.redhat.com/show_bug.cgi?id=2464263
Resource:
issue-tracking
x_refsource_REDHAT
▼Authorized Data Publishers (ADP)
CISA ADP Vulnrichment
Affected Products
Metrics
VersionBase scoreBase severityVector
Metrics Other Info
Impacts
CAPEC IDDescription
Solutions
Configurations
Workarounds
Exploits
Credits
Timeline
EventDate
Replaced By
Rejected Reason
References
HyperlinkResource
Information is not available yet
▼National Vulnerability Database (NVD)
nvd.nist.gov
Source:secalert@redhat.com
Published At:19 May, 2026 | 12:16
Updated At:19 May, 2026 | 12:16

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

CISA Catalog
Date AddedDue DateVulnerability NameRequired Action
N/A
Date Added: N/A
Due Date: N/A
Vulnerability Name: N/A
Required Action: N/A
Metrics
TypeVersionBase scoreBase severityVector
Primary3.17.1HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Type: Primary
Version: 3.1
Base score: 7.1
Base severity: HIGH
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
CPE Matches
Weaknesses
CWE IDTypeSource
CWE-472Primarysecalert@redhat.com
CWE ID: CWE-472
Type: Primary
Source: secalert@redhat.com
Evaluator Description
Evaluator Impact

Evaluator Solution

Vendor Statements
References
HyperlinkSourceResource
https://access.redhat.com/security/cve/CVE-2026-7571secalert@redhat.com
N/A
https://bugzilla.redhat.com/show_bug.cgi?id=2464263secalert@redhat.com
N/A
Hyperlink: https://access.redhat.com/security/cve/CVE-2026-7571
Source: secalert@redhat.com
Resource: N/A
Hyperlink: https://bugzilla.redhat.com/show_bug.cgi?id=2464263
Source: secalert@redhat.com
Resource: N/A

Change History

0
Information is not available yet

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Details not found