CVE-2026-0871 | Org.keycloak/keycloak-services: keycloak: unauthorized modification of unmanaged user attributes by administrators

A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to unauthorized changes to user profiles, even when the system is configured to restrict such modifications.

Published: 2026-02-27 Last update: 2026-03-05 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-0871 is rated Low Risk (21.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-0871

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-02-27 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-0871

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 3.6 [email protected]

Weakness enumeration for CVE-2026-0871

GitHub Security Advisory for CVE-2026-0871

GHSA-v4jw-m6rm-399h · Severity: medium · Ecosystem: maven — Keycloak Server Private SPI: Improper Access Control Allows Administrators to Bypass Attribute Visibility Restrictions and Modify Unmanaged User Profile Attributes

OS Trackers for CVE-2026-0871

vendor priority summary link
alpine — CVE-2026-0871: 1 source package rows (keycloak); 10 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 10. https://security.alpinelinux.org/vuln/CVE-2026-0871
redhat medium — https://access.redhat.com/security/cve/CVE-2026-0871

Affected software / configurations for CVE-2026-0871

Vendor Product Version Raw CPE
redhat build_of_keycloak < 26.4.9 cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:*
redhat build_of_keycloak — cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:text-only:*:*:*
redhat keycloak < 26.4.0 cpe:2.3:a:redhat:keycloak:*:*:*:*:*:*:*:*

References for CVE-2026-0871

cvelogic Threat Intelligence