ChangeIntelIT change radar
Public mode

No access to your tenant or devices. Every item links to its source. What this means

Some sources, documents or advisories need attention: 272/272 feeds/APIs · 469/469 docs · 8/9 advisories · checked 19:51 UTC Customize Public modeDiscuss ChangeIntel on Discord
CVE-2026-93628Published

Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar REPLY Attendee Response

Exact source revision recorded 23 Oct 2026 16:01:20 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

cve-program · CVE-2026-93628

Published

An attendee authentication vulnerability in the email calendar processing of Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to forge another attendee's response to an existing meeting. Zimbra passes a null sender identity when processing iCalendar REPLY components, causing the attendee authorization filter to be skipped. An attacker who knows the meeting UID, organizer address and attendee address can send a non-outdated reply that changes the attendee's participation status in the organizer's calendar. The change occurs automatically during delivery without organizer or attendee interaction. ZCS 10.1.16 and 10.1.21 are affected.

Source published
23 Oct 2026 13:18:16 UTC
Source modified
23 Oct 2026 13:18:16 UTC
Observed here
23 Oct 2026 16:01:20 UTC
Source terms
CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

ChangeIntel

An IT change radar: releases, security, known issues, retirements, documentation changes, and service status from public sources. Every item links to supporting evidence; dates and statuses can change after they are read.

Sources read 27 Oct 19:51 UTC · 272 of 272 readable · 270 fully read · documentation 469/469 current

No accounts or analytics; your preferences stay in your browser. Information, not advice. ChangeIntel is an independent tool and is not affiliated with or endorsed by Microsoft, Apple, Google, Broadcom (VMware), Jamf, Oracle, Mozilla, or any other vendor it covers. Product names are trademarks of their owners. Built by Evotec.