AUGUST 5, 2026
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Case File

CVE-2023-51766

MEDIUM · CVSS 5.3 EPSS 1.08% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2023-12-24 · Last synced 2026-08-04

CyberRota Analysis

This is a medium severity vulnerability with a CVSS score of 5.3. Public exploit code or proof-of-concept references have been detected in its references. It may be remotely exploitable.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit
GitHub PoC Links

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2023-51766
Severity
MEDIUM
CVSS
5.3
EPSS
1.08%

Original NVD Description

Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some other popular e-mail servers do not.

Related CVEs

Other vulnerabilities affecting the same vendor(s)