CVE-2026-93631
Awaiting Analysis Awaiting Analysis - Queue

BaseFortify

Vulnerability report for CVE-2026-93631, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-23

Last updated on: 2026-10-23

Assigner: Rapid7, Inc.

Description

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.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-10-23
Last Modified
2026-10-23
Generated
2026-10-23
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
Zimbra Zimbra Collaboration Suite 0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-352 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.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
AI Quick Actions have not been generated yet.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-93631. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart