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TI-2026-69620 Aliases CVE-2026-50054GHSA-6c75-c59q-9624

Zimbra Collaboration Suite flaw lets accounts grant mailbox access

Priority LOW 30CWE-269Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-269.

Summary

Zimbra Collaboration Suite before 10.1.20 contains an authorization flaw in the GrantRightsRequest SOAP handler. An attacker with access to an authenticated account can grant another local account the loginAs right, which creates persistent mailbox access and mail-sending authority that survives password changes and session expiry. The flaw is classified as CWE-269 (Improper Privilege Management).

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

An authorization flaw in Zimbra Collaboration Suite’s GrantRightsRequest allows an attacker with access to an authenticated account to grant another local account the loginAs right, creating persistent mailbox access and mail-sending authority that survives password changes and session expiry.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00171 6th percentileScored 2026-11-07
Fix Fixed Zimbra Collaboration Suite (Zimbra): 10.1.20

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

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 Suitebefore 10.1.2010.1.20Patch availableCNA
  • Zimbra Collaboration Suite VendorZimbra Affected before 10.1.20 Fixed in 10.1.20 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*——Synacor
  • cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* Versions — — ·Synacor

Remediation

Zimbra Collaboration Suite users should upgrade to version 10.1.20. The sources list no fixed version for any other product line.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA Zimbra Collaboration Suite (Zimbra) Fixed in 10.1.20

Fixed in the same release

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

  • Release ·

    Zimbra Collaboration Suite 10.1.20

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-69621 Sieve notify action bypasses mail forwarding restriction in ZimbraPriority LOW 29
    • TI-2026-69618 Zimbra Collaboration Suite EWS authorization bypass exposes mailboxesPriority LOW 29
    Show all 3 records →

Timeline

  1. 2026-10-08 Threatist record created from CVE-2026-50054
  2. 2026-10-08 CISA SSVC decision points changed
  3. 2026-10-09 Alias added: GHSA-6c75-c59q-9624
  4. 2026-10-09 Priority changed: MEDIUM → LOW

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