---
cve: "CVE-2026-93631"
severity: "HIGH"
cvss: 7.1
epss: "0.1%"
vendor: "Zimbra"
kev: false
exploited: false
published: "2026-10-23 13:23:34"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-10-28T20:14:41+01:00"
---

# CVE-2026-93631

> 7.1 HIGH

## Beschreibung

A cross-site request forgery vulnerability in the OAuth extension of Zimbra Collaboration Suite (ZCS) Network Edition allows an attacker to link an attacker-controlled external account to a victim's mailbox. The OAuth callback does not bind its state value or authorization code to the initiating Zimbra session and instead selects the destination mailbox from the browser's current authentication cookie. On a deployment with the provider configured, an attacker can induce a signed-in victim to load a callback containing a fresh code for the attacker's provider account. This creates a persistent data source that imports attacker-controlled contacts or events. With bidirectional CalDAV synchronization, appointments subsequently created or edited in the linked calendar are also disclosed to the attacker. ZCS 10.1.16 and 10.1.20 are affected.

## CNA-Record (Kanon, cvelistV5)

- CNA: **rapid7**
- State: PUBLISHED
- Stand: 2026-10-23 13:23:34
- CNA-CVSS: **7.1** (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N`)

## CVSS-Vektor

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

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

## Schwachstellen-Klasse

- **CWE-352** — Cross-Site Request Forgery (CSRF)
  The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.

## Angriffsmuster (CAPEC)

- [CAPEC-62 — Cross Site Request Forgery](https://capec.mitre.org/data/definitions/62.html) _(Severity: Very High)_
- [CAPEC-111 — JSON Hijacking (aka JavaScript Hijacking)](https://capec.mitre.org/data/definitions/111.html) _(Severity: High)_
- [CAPEC-462 — Cross-Domain Search Timing](https://capec.mitre.org/data/definitions/462.html) _(Severity: Medium)_
- [CAPEC-467 — Cross Site Identification](https://capec.mitre.org/data/definitions/467.html) _(Severity: Low)_

## Referenzen

- <https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories>
- <https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-93631/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_