CVE-2026-50053 Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL Parameters

A request attribute override vulnerability in Zimbra Collaboration Suite ZCS allows unauthenticated requests to /h/ to populate servlet attributes intended for trusted internal dispatch. RestFilter copies URL parameters specifying an authentication token, target account, target item and dispatch...

CVE-2026-50053

The Zimbra Collaboration Suite (ZCS) contains a request attribute override vulnerability where unauthenticated requests to /h/* can populate servlet attributes used for trusted internal dispatch. The RestFilter component improperly copies URL parameters—including authentication tokens , target ac...

CVE-2026-10632 Zimbra Collaboration Suite Classic Web Client Reflected Cross-Site Scripting via Document Editor Packages Parameter

A reflected cross-site scripting vulnerability in the Classic Web Client of Zimbra Collaboration Suite ZCS allows an attacker to inject JavaScript through the packages parameter of the /h/rest document editor. The editor inserts package names into script attributes without HTML encoding. When...

CVE-2026-10632

A reflected cross-site scripting (XSS) vulnerability exists in the Classic Web Client of Zimbra Collaboration Suite (ZCS) . The root cause is the lack of HTML encoding when the document editor inserts package names into script attributes via the /h/rest endpoint's packages parameter. When chained...

Zimbra - Cross-Site Scripting via ICS Files

Detects Zimbra Collaboration Suite versions vulnerable to CVE-2025-27915, a stored XSS vulnerability in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an email with a malicious ICS entry, embedded JavaScript executes via an ontoggle event...

CVE-2026-93647 Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Crafted Calendar COUNTER Message From Address

An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim...

CVE-2026-93647

The Zimbra Collaboration Suite Classic Web Client is vulnerable to a stored Cross-Site Scripting (XSS) flaw. An unauthenticated calendar sender can inject active markup into the RFC From address of a COUNTER message . When a user selects this message within Zimbra Classic, the XSS is triggered, p...

CVE-2026-93647 Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Crafted Calendar COUNTER Message From Address

An unauthenticated calendar sender can place active markup in a COUNTER message's RFC From address. Selecting the message in Zimbra Classic triggers stored XSS, allowing the attacker to access mailbox data and act as the victim...

CVE-2026-93641

The Zimbra Collaboration Suite Classic Web Client is vulnerable to Stored Cross-Site Scripting (XSS) . An unauthenticated sender can forge a share notification that, when clicked by a signed-in recipient, executes malicious scripts. This allows an attacker to access mailbox data and act as the vi...

CVE-2026-93641 Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Forged Share Invitation

An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Classic recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim...

When Business Email Compromise Starts Rewriting Reality

Business Email Compromise BEC operates on a familiar playbook. Threat actors breach a mailbox, silently monitor operations, map approval chains, and ultimately exploit that access to divert funds or exfiltrate sensitive assets. This dynamic is central to our analysis as we kick off a series aroun...

CVE-2026-73572

In Zimbra Collaboration ZCS before 10.1.17, a stored cross-site scripting XSS vulnerability exists in the Zimbra Classic Web Client due to insufficient sanitization of specific attachment content during inline preview. An attacker can send a crafted email containing a malicious attachment that,...

CVE-2026-73574

Zimbra Collaboration versions before 10.1.17 are affected by a local file inclusion (LFI) vulnerability in the Forward servlet of the Classic Web Client. The root cause is improper validation of the fu request parameter, allowing an unauthenticated attacker to supply a crafted path and disclose p...

CVE-2026-73572

In Zimbra Collaboration ZCS before 10.1.17, a stored cross-site scripting XSS vulnerability exists in the Zimbra Classic Web Client due to insufficient sanitization of specific attachment content during inline preview. An attacker can send a crafted email containing a malicious attachment that,...

EUVD-2026-58071

In Zimbra Collaboration ZCS before 10.1.17, a stored cross-site scripting XSS vulnerability exists in the Zimbra Classic Web Client due to insufficient sanitization of specific attachment content during inline preview. An attacker can send a crafted email containing a malicious attachment that,...

CVE-2026-73574: Incorrect Resource Transfer Between Spheres

In Zimbra Collaboration before 10.1.17, a local file inclusion LFI vulnerability exists in the Zimbra Classic Web Client due to improper validation of the fu request parameter. An unauthenticated attacker can exploit this vulnerability by supplying a crafted path, potentially allowing unauthorize...

PT-2026-71678

Name of the Vulnerable Software and Affected Versions Zimbra Collaboration ZCS versions prior to 10.1.17 Description A stored cross-site scripting XSS issue exists in the Zimbra Classic Web Client. This occurs because the system does not sufficiently sanitize specific attachment content during...

CVE-2026-73572: Improper Neutralization of Input During Web Page Generation

In Zimbra Collaboration ZCS before 10.1.17, a stored cross-site scripting XSS vulnerability exists in the Zimbra Classic Web Client due to insufficient sanitization of specific attachment content during inline preview. An attacker can send a crafted email containing a malicious attachment that,...

Zimbra - Cross-Site Scripting via ICS Files Detection

Detects Zimbra Collaboration Suite versions vulnerable to CVE-2025-27915, a stored XSS vulnerability in the Classic Web Client due to insufficient sanitization of HTML content in ICS files. When a user views an email with a malicious ICS entry, embedded JavaScript executes via an ontoggle event...

Critical Zimbra Flaw Could Let Crafted Emails Run Malicious Code in User Sessions

Zimbra is urging customers to apply updates to address a critical security vulnerability impacting the Classic Web Client that could result in arbitrary code execution. The vulnerability has been described as a case of stored cross-site scripting XSS that could allow specially crafted emails to...