CVE-2026-37982: Keycloak: org.keycloak.authentication: keycloak: unauthorized account takeover via webauthn token replay

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-19 · updated 2026-10-29
Weakness: CWE-294

Description

A flaw was found in Keycloak. This authentication vulnerability allows a remote attacker to replay `ExecuteActionsActionToken` tokens within Keycloak's WebAuthn (Web Authentication) flow. By intercepting an execute-actions email link, an attacker can register their own authenticator to a victim's account. This leads to unauthorized enrollment of a hardware-backed credential, enabling persistent account takeover.

Affected products

Red Hat build of Keycloak 26.4: from 26.4 before 26.4.12 — fixed in 26.4.12
Red Hat build of Keycloak 26.4: all versions — fixed in 26.4.12-1

How to fix

Upgrade to a fixed version: Red Hat build of Keycloak 26.4 26.4.12; Red Hat build of Keycloak 26.4 26.4.12-1. Check the vendor advisory for mitigations.

References

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