---
cve: "CVE-2026-9087"
severity: "MEDIUM"
cvss: 6.4
epss: "31%"
vendor: "Red Hat"
kev: false
exploited: false
published: "2026-05-20 17:16:32"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T08:54:31+02:00"
---

# CVE-2026-9087

> 6.4 MEDIUM

## Beschreibung

A flaw was found in Keycloak. The cross-session verification proof is keyed only by (local userId,
idpAlias) and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Hoch | good |
| PR Privilegien | Gering | warn |
| UI Interaktion | Erforderlich | good |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Referenzen

- <https://access.redhat.com/errata/RHSA-2026:25097>
- <https://access.redhat.com/errata/RHSA-2026:25098>
- <https://access.redhat.com/errata/RHSA-2026:30049>
- <https://access.redhat.com/errata/RHSA-2026:30050>
- <https://access.redhat.com/security/cve/CVE-2026-9087>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2480172>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-9087) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_