CVE-2026-3872
Keycloak: Redirect URI validation bypass via ..;/ path traversal in OIDC auth endpoint
7.3
HIGH
CVSS 3.1
EPSS 0.01%
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.
How to fix CVE-2026-3872
To remediate CVE-2026-3872, upgrade the affected package to a fixed version below.
- —upgrade to 26.5.7 or later
Is CVE-2026-3872 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 26.5.7
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.3 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N |