CVE-2026-16442
Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction
No known exploitation. EPSS puts it in the 22nd percentile. A vendor fix is available.
What to do
The vendor has published a fix. Version details are below where the sources state them.
What it is
From the CVE record
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.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.3% chance of exploitation activity in the next 30 days, which ranks it in the 22nd percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
11 events over 5 days, from the signal feeds we watch.
- Patch availableworkaround available, record updated
- OpenVAS check added
- Workaround availablerecord updated
- Workaround availableworkaround available, published, weakness classified, record updated
Affected products
- Red Hat build of Keycloak 26.4Web & CMS Plugins
- Red Hat build of Keycloak 26.4.14Operating Systems / linux-distro
- Red Hat build of Keycloak 26.6Security Products / identity-access-mgmt
- Red Hat build of Keycloak 26.6.5Operating Systems / linux-distro
- Red Hat Data Grid 8Databases / cache-message-queue
- Red Hat JBoss Enterprise Application Platform Expansion PackOperating Systems / linux-distro
- Red Hat Single Sign-On 7Security Products / identity-access-mgmt
- build of keycloakOperating Systems / linux-distro
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Scored 7.4 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
- Privileges Required NoneNo authentication required — anyone can exploit this
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope UnchangedImpact is limited to the vulnerable component itself
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability NoneNo availability impact
Weaknesses
Sources
References in the record
- access.redhat.com/errata/RHSA-2026:50846
- access.redhat.com/errata/RHSA-2026:50847
- access.redhat.com/errata/RHSA-2026:50848
And 3 more references. See all after sign-in
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