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7.3
HIGH CVSS 3.1
CVE-2026-15571
Keycloak-services: keycloak-services: predictable account-linking hash enables account takeover via malicious oidc client
Overview
Description

A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.

Details
INFO

Published Date :

Aug. 18, 2026, 9:16 p.m.

Last Modified :

Aug. 19, 2026, 3:16 a.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Impact
Affected Products

The following products are affected by CVE-2026-15571 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Redhat single_sign-on
2 Redhat data_grid
3 Redhat build_of_keycloak
: Total Affected Vendor : 1 | Products : 3
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 53f830b8-0a3f-465b-8143-3b8a9948e749
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
Solution
Update Keycloak to fix a flaw in the account linking endpoint that allows account takeover.
  • Update Keycloak to the latest version.
  • Apply necessary security patches.
  • Review account linking configurations.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-15571.

URL Resource
https://access.redhat.com/errata/RHSA-2026:56523
https://access.redhat.com/errata/RHSA-2026:56524
https://access.redhat.com/security/cve/CVE-2026-15571
https://bugzilla.redhat.com/show_bug.cgi?id=2499591
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-15571 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-15571 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-15571 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-15571 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Aug. 19, 2026

    Action Type Old Value New Value
    Changed Affected [{'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6.6-1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-operator-bundle-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-operator-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk-openshift-rhel9/rhbk-openshift-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jboss_data_grid:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Data Grid 8', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/jbossnetwork/restricted/listSoftware.html', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:red_hat_single_sign_on:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Single Sign-On 7', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}] [{'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6.6-1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-operator-bundle', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-rhel9-operator', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk-openshift-rhel9/rhbk-openshift-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jboss_data_grid:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Data Grid 8', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/jbossnetwork/restricted/listSoftware.html', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:red_hat_single_sign_on:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Single Sign-On 7', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}]
  • New CVE Received by [email protected]

    Aug. 18, 2026

    Action Type Old Value New Value
    Added Affected [{'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6.6-1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-operator-bundle-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6', 'versions': [{'status': 'unaffected', 'version': '26.6-12', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'keycloak-rhel9-operator-container', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.6'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.6.6', 'packageName': 'rhbk-openshift-rhel9/rhbk-openshift-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jboss_data_grid:8'], 'vendor': 'Red Hat', 'product': 'Red Hat Data Grid 8', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:jbosseapxp'], 'vendor': 'Red Hat', 'product': 'Red Hat JBoss Enterprise Application Platform Expansion Pack', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/jbossnetwork/restricted/listSoftware.html', 'defaultStatus': 'unaffected'}, {'cpes': ['cpe:/a:redhat:red_hat_single_sign_on:7'], 'vendor': 'Red Hat', 'product': 'Red Hat Single Sign-On 7', 'packageName': 'keycloak-services', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}]
    Added Description A flaw was found in the legacy client-initiated account-linking endpoint of Keycloak, a widely used open-source identity and access management solution. The mechanism used to protect the account-linking process from unauthorized requests relies on a hash that can be predicted by a malicious OIDC client. By tricking a user into authenticating, an attacker-controlled client can forge a valid linking URL to connect the victim's account to an attacker's external identity. This results in a full account takeover, allowing the attacker to log in as the victim.
    Added CVSS V3.1 AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
    Added CWE CWE-341
    Added Reference https://access.redhat.com/errata/RHSA-2026:56523
    Added Reference https://access.redhat.com/errata/RHSA-2026:56524
    Added Reference https://access.redhat.com/security/cve/CVE-2026-15571
    Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2499591
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.3
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact