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TI-2026-63081 Aliases CVE-2026-93647GHSA-h5jf-rfhh-rx8c

Cross-site scripting in Zimbra Collaboration Suite

Priority MEDIUM 41CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00229 13th percentileScored 2026-11-07
Fix Fixed Zimbra Collaboration Suite (ZCS) (Zimbra): 10.1.21

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZimbraZimbra Collaboration Suite (ZCS)before 10.1.2110.1.21Patch availableCNA
  • Zimbra Collaboration Suite (ZCS) VendorZimbra Affected before 10.1.21 Fixed in 10.1.21 Patch available CNA

Remediation

  • Fix · CNA Zimbra Collaboration Suite (ZCS) (Zimbra) Fixed in 10.1.21

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Zimbra Collaboration Suite (ZCS) 10.1.21

    4 records Highest priority Priority MEDIUM 4 MEDIUM

    Other records, highest priority first

    • TI-2026-63080 Path traversal in Zimbra Collaboration SuitePriority MEDIUM 51
    • TI-2026-63078 Zimbra Collaboration Suite Classic Web Client Stored Cross-Site Scripting via Forged Share InvitationPriority MEDIUM 42
    • TI-2026-63079 Zimbra Collaboration Suite Modern Web Client Stored Cross-Site Scripting via Forged Share InvitationPriority MEDIUM 41
    Show all 4 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-93647
  2. 2026-10-03 Alias added: GHSA-h5jf-rfhh-rx8c

References

Advisory 1

  • TI-2026-51660 OS command injection in Zimbra Collaboration KEVCVSS 3.1HIGH 8.9
  • TI-2025-40820 Cross-site scripting in Zimbra Collaboration KEVCVSS 3.1HIGH 7.2
  • TI-2024-18266 An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0. KEVCVSS 3.1MEDIUM 6.1
  • TI-2024-30553 An issue was discovered in Zimbra Collaboration (ZCS) 10.1.x before 10.1.1, 10.0.x before… CVSS 3.1HIGH 8.8
  • TI-2022-13998 Zimbra Collaboration Open Source 8.8.15 does not encrypt the initial-login randomly… CVSS 3.1CRITICAL 9.8
  • TI-2026-63080 Path traversal in Zimbra Collaboration Suite CVSS 3.1CRITICAL 9.8
See all 94 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences