Security readout for executives and security teams
Plain-English summary
CVE-2026-0871 is an access-control flaw in Keycloak-related Red Hat products. A highly privileged administrator with manage-users permission can change unmanaged user attributes even when configuration says those attributes should only be viewable by administrators. The main business risk is unauthorized profile integrity changes inside identity systems, not public remote takeover.
Executive priority
Treat as a medium-priority identity governance issue. It is not described as actively exploited and needs high privileges, but it affects identity data integrity. Prioritize if your organization uses delegated administrators, stores sensitive business attributes in user profiles, or relies on attribute controls for compliance workflows.
Technical view
The flaw is CWE-266 improper privilege/access control. Red Hat describes a bypass of the “Only administrators can view” setting for unmanaged attributes by administrators holding manage-users. CVSS is 4.9, network reachable, low complexity, high privileges required, no user interaction, with high integrity impact and no confidentiality or availability impact stated.
Likely exposure
Exposure is limited to environments using affected Red Hat Keycloak builds or packages listed by Red Hat, including Red Hat build of Keycloak 26.4 packages and keycloak-services in listed Red Hat products. It requires an authenticated administrator with manage-users permission, so insider risk, delegated admin models, and compromised admin accounts matter most.
Exploitation context
The provided sources do not indicate active exploitation, and CISA KEV status is false. Exploitation requires high privileges, reducing broad internet risk. The realistic scenario is abuse by an over-privileged, malicious, or compromised administrator to alter user profile data despite attribute visibility restrictions.
Researcher notes
Key unknowns from the provided bundle include exact upstream Keycloak version ranges and detailed fixed package versions beyond Red Hat’s affected/unaffected product entries. Avoid assuming community Keycloak exposure unless confirmed by vendor data. Focus validation on role-based permissions, unmanaged attribute configuration, and Red Hat package provenance.
Mitigation direction
- Review Red Hat advisories RHSA-2026:2365 and RHSA-2026:2366 for applicable updates.
- Upgrade affected Red Hat packages to vendor-designated fixed or unaffected versions.
- Audit who has manage-users permission in each Keycloak realm.
- Reduce delegated admin permissions where business need is not clear.
- Monitor user attribute changes until updates and permission reviews are complete.
Validation and detection
- Inventory Keycloak, Red Hat build of Keycloak, RH-SSO, and JBoss/EAP components.
- Compare installed packages and versions against Red Hat’s affected product list.
- Confirm whether unmanaged attributes use the “Only administrators can view” setting.
- Review admin role assignments for manage-users permission.
- Check audit logs for unexpected unmanaged user attribute modifications.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-266: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-0871 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 4.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N1.23.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.9MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2026:2365CVE reference · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:2366CVE reference · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0871CVE reference · vdb-entry, x_refsource_REDHAT
- RHBZ#2428881CVE reference · issue-tracking, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Privilege Assignment
Incorrect Privilege Assignment represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.