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TI-2026-79896 Aliases CVE-2026-115785GHSA-m4x2-65hq-rqw6

SMTP command injection in Zimbra Collaboration Suite data source test

Priority LOW 23CWE-93Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Zimbra Collaboration Suite versions through 10.1.20 are affected, and the vulnerable command-construction path is present in 10.1.16 and 10.1.20. The data-source test function does not neutralize CR/LF characters in the email address it places into an SMTP envelope command (CWE-93). An ordinary authenticated user with account options enabled can inject SMTP commands, and after a successful POP3 or IMAP login the injected commands reach the selected SMTP service. If that service accepts the pipelined transaction, the attacker can submit mail with chosen recipients, headers and body without victim interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

An SMTP command injection vulnerability in the data-source testing functionality of Zimbra Collaboration Suite (ZCS) allows an ordinary authenticated user with account options enabled to inject CR/LF into the emailAddress inserted into an SMTP envelope command by a JSON SOAP request. After a successful preliminary POP3 or IMAP login, Zimbra sends the injected commands to the selected SMTP service. If that service accepts the pipelined transaction, the attacker can submit mail with attacker-selected recipients, headers and body content without victim interaction. The vulnerable command-construction path is present in ZCS 10.1.16 and 10.1.20.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00748 55th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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 Suiteup to 10.1.20—No fix listedCNA
  • Zimbra Collaboration Suite VendorZimbra Affected up to 10.1.20 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*up to 10.1.20VulnerableSynacor
  • cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* Versions up to 10.1.20 Vulnerable ·Synacor

Remediation

The sources list no fixed version for Zimbra Collaboration Suite.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Timeline

  1. 2026-10-23 Threatist record created from CVE-2026-115785
  2. 2026-10-23 Alias added: GHSA-m4x2-65hq-rqw6
  3. 2026-10-24 CISA SSVC decision points changed
  4. 2026-10-29 CISA SSVC decision points changed

References

Advisory 1

Other 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