CVE-2026-93627— Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar CANCEL/REQUEST Organizer
Quick assessment
Affected
Zimbra Zimbra Collaboration Suite
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Zimbra 协作套件（ZCS）的邮件日历处理功能中存在一个组织身份验证漏洞，允许未认证的发件人取消或修改收件人日历中已存在的会议。Zimbra 在接收 iCalendar 的 CANCEL（取消）和 REQUEST（请求）组件时，未验证邮件发件人是否有权以所指定的组织身份执行操作。攻击者若知晓会议的 UID（唯一标识符）和组织者地址，便可提供未过期的序列号，将收件人的会议移至垃圾桶或替换其详细信息。该处理过程在邮件投递期间自动执行，无需收件人任何交互。受影响的版本为 ZCS 10.1.16 和 10.1.21。
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-93627
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar CANCEL/REQUEST Organizer
Source: CVE Program / CVE List V5
Vulnerability Description
An organizer authentication vulnerability in the email calendar processing of Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to cancel or modify an existing meeting in a recipient's calendar. Zimbra accepts iCalendar CANCEL and REQUEST components without verifying that the email sender is authorized to act as the supplied organizer. An attacker who knows the meeting UID and organizer address can supply a non-outdated sequence number to move the recipient's meeting to Trash or replace its details. Processing occurs automatically during email delivery without recipient interaction. ZCS 10.1.16 and 10.1.21 are affected.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
使用欺骗进行的认证绕过
Source: CVE Program / CVE List V5
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Zimbra | Zimbra Collaboration Suite | 0 ~ 10.1.21 | - |
|
II. Public POCs for CVE-2026-93627
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-93627
请登录查看更多情报信息。
Vendor Advisories for CVE-2026-93627 (1)
-
Zimbra Security Advisories - Zimbra :: Tech Center vendor-advisory
Other References for CVE-2026-93627 (1)
Same Patch Batch · Zimbra · 2026-10-23 · 17 CVEs total
| CVE-2026-10632 | 8.7 HIGH | Zimbra Collaboration Suite Classic Web Client Reflected Cross-Site Scripting via Document |
| CVE-2026-50053 | 8.7 HIGH | Zimbra Collaboration Suite RestFilter Request Attribute Override via Unauthenticated URL P |
| CVE-2026-93639 | 8.7 HIGH | Zimbra Collaboration Suite Missing Authorization in ConfigureZimlet Enables Delegated Admi |
| CVE-2026-93640 | 7.8 HIGH | Zimbra Collaboration Suite Local Privilege Escalation via Unrestricted zmunbound Sudo Conf |
| CVE-2026-50056 | 7.8 HIGH | Zimbra Collaboration Suite Local Privilege Escalation via zmmailboxdmgr JVM Argument Injec |
| CVE-2026-50057 | 7.8 HIGH | Zimbra Collaboration Suite Local Privilege Escalation via Unrestricted Postfix Sudo Permis |
| CVE-2026-93631 | 7.1 HIGH | Zimbra Collaboration Suite OAuth Extension Cross-Site Request Forgery Enables Account Link |
| CVE-2026-115786 | 6.5 MEDIUM | Zimbra Collaboration Suite Shared-File Mailbox Quota Accounting Error Enables Quota Exhaus |
| CVE-2026-93638 | 6.1 MEDIUM | Zimbra Collaboration Suite Pre-Authentication Reflected Cross-Site Scripting via Login Pag |
| CVE-2026-93633 | 5.4 MEDIUM | Zimbra Collaboration Suite Briefcase CSS Sanitization Bypass via Non-ASCII Stylesheet Char |
| CVE-2026-93629 | 5.3 MEDIUM | Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar |
| CVE-2026-93628 | 5.3 MEDIUM | Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar |
| CVE-2026-93630 | 4.3 MEDIUM | Zimbra Collaboration Suite Email HTML Sanitizer Bypass via Hostname Canonicalization |
| CVE-2026-93634 | 4.3 MEDIUM | Zimbra Collaboration Suite Cross-Account Authorization Bypass via Forged Shared-File Recor |
| CVE-2026-93636 | 4.3 MEDIUM | Zimbra Collaboration Suite LDAP Filter Injection via Calendar Resource Attribute Name |
| CVE-2026-115785 | 4.3 MEDIUM | Zimbra Collaboration Suite Data Source Test SMTP Command Injection via Unsanitized Email A |
IV. Related Vulnerabilities
Same product: Zimbra Collaboration Suite
-
CVE-2026-115786
Zimbra Collaboration Suite Shared-File Mailbox Quota Account -
CVE-2026-115785
Zimbra Collaboration Suite Data Source Test SMTP Command Inj -
CVE-2026-93640
Zimbra Collaboration Suite Local Privilege Escalation via Un -
CVE-2026-50057
Zimbra Collaboration Suite Local Privilege Escalation via Un -
CVE-2026-50056
Zimbra Collaboration Suite Local Privilege Escalation via zm
Same vendor: Zimbra
-
CVE-2026-115786
Zimbra Collaboration Suite Shared-File Mailbox Quota Account -
CVE-2026-115785
Zimbra Collaboration Suite Data Source Test SMTP Command Inj -
CVE-2026-93640
Zimbra Collaboration Suite Local Privilege Escalation via Un -
CVE-2026-50057
Zimbra Collaboration Suite Local Privilege Escalation via Un -
CVE-2026-50056
Zimbra Collaboration Suite Local Privilege Escalation via zm
Same weakness: CWE-290
-
CVE-2026-93629
Zimbra Collaboration Suite Calendar Processing Authenticatio -
CVE-2026-93628
Zimbra Collaboration Suite Calendar Processing Authenticatio -
CVE-2025-30052
Authentication Bypass via IP Spoofing in CGM CLININET rsyncd -
CVE-2022-51026
Bytebase 0.12.0 before 1.0.1 Authentication Bypass via GitLa -
CVE-2026-112241
WordPress SureCart plugin <= 4.9.5 - Broken Authentication v
V. Comments for CVE-2026-93627
No comments yet