Keycloak 26.4.x < 26.4.15 / 26.6.x < 26.6.6 Unauthenticated Account Takeover

critical Nessus Plugin ID 338317

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Synopsis

The remote host is affected by an account takeover vulnerability.

Description

The version of Keycloak installed on the remote host is 26.4.x prior to 26.4.15, or 26.6.x prior to 26.6.6. It is, therefore, affected by a vulnerability:

- A flaw was found in the reset-credentials flow of the keycloak-services component, which is the core engine for identity and access management. The issue allows an unauthenticated attacker to force the password reset process for any user without needing to click the required email verification link. This can result in the attacker gaining full control over target user accounts by directly setting new credentials. (CVE-2026-18963)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade Keycloak to version 26.4.15 / 26.6.6 or later.

Plugin Details

Severity: Critical

ID: 338317

File Name: keycloak_26_4_15.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 8/20/2026

Updated: 8/20/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.51

CVSS v2

Risk Factor: High

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-18963

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Vulnerability Information

CPE: cpe:/a:keycloak:keycloak

Required KB Items: Host/local_checks_enabled, Host/uname, installed_sw/Keycloak

Patch Publication Date: 8/18/2026

Vulnerability Publication Date: 8/17/2026

Reference Information

CVE: CVE-2026-18963

Detections

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