CVE-2026-115785
MEDIUM 4.3An 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.7%chance of exploitation in 30 days · 54th percentile
Impact if exploited
4.3CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityLow
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-93: Improper neutralization of CRLF sequences ('CRLF injection')
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
References and research data (JSON)
All CVSS metrics
- MEDIUM 4.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N - MEDIUM 4.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
References
Advisories
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories CVE record · rapid7 · Updated 2026-10-23T13:50:33.115Z
NVD · CVE-2026-115785 · Updated 2026-10-24T04:18:17.737 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-109079 EUVD · EUVD-2026-109079
Technical & other
- https://www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1/ CVE record · rapid7 · Updated 2026-10-23T13:50:33.115Z
NVD · CVE-2026-115785 · Updated 2026-10-24T04:18:17.737