CVE-2026-93647Critical· 9.3▾ MidnightAn 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.
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 51.2 · likelihood 0 · exploitation 0
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Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 27.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
Last analysed / modified upstream
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.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-93642Critical· 9.3An unauthenticated sender can forge a share notification that triggers stored XSS when a signed-in Zimbra Modern recipient clicks Accept Share, allowing the attacker to access mailbox data and act as the victim.
CVE-2026-93641Critical· 9.3An 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.
CVE-2026-93633Medium· 5.4Zimbra Collaboration Suite Briefcase CSS Sanitization Bypass via Non-ASCII Stylesheet Characters
CVE-2026-93638Medium· 6.1Zimbra Collaboration Suite Pre-Authentication Reflected Cross-Site Scripting via Login Page zrememberme Parameter
CVE-2026-10632High· 8.7Zimbra Collaboration Suite Classic Web Client Reflected Cross-Site Scripting via Document Editor Packages Parameter
CVE-2026-93643Critical· 9.8When OnlyOffice/Document Editing is available, an unauthenticated remote attacker with access to an existing supported public Briefcase document can abuse unsigned save fields to perform path-traversal writes and execute commands as zimbra.