High severity · published Apr 2, 2026
CVE-2026-3872
Keycloak: keycloak: information disclosure due to redirect_uri validation bypass
7.3
CVSS
0.4%
EPSS
No
On KEV
Description
A flaw was found in Keycloak. This issue allows an attacker, who controls another path on the same web server, to bypass the allowed path in redirect Uniform Resource Identifiers (URIs) that use a wildcard. A successful attack may lead to the theft of an access token, resulting in information disclosure.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat build of Keycloak 26.2 · Red Hat
All versions, or not specified · source: vendor, CISA
RH
Red Hat build of Keycloak 26.4 · Red Hat
All versions, or not specified · source: vendor, CISA
BO
Build OF Keycloak · Redhat
26.2; 26.2.15; 26.4; 26.4.11 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-3872
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-3872
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6475
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6476
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6477
Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:6478
Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-3872
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2445988
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