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UK Cyber Defence
VulnerabilityUndergoing Analysis

CVE-2026-115785

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…

MEDIUM 4.3EPSS 0.73%

Does this matter?

Lower severity and a low EPSS score (0.73%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
EPSS
0.73% probability · 54th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-93
Source
cve@rapid7.com
EPSS trend
0%3%5%24 October 2026: 0.98%26 October 2026: 0.73%24 October 202626 October 2026

EPSS moved from 1.0% on 24 October 2026 to 0.7% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.