VulnSocial

CVE-2023-51766Patch(debian / debian_linux)

LOWCVSS 5.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch debian debian_linux systems immediately

Recommended action window: Monitor and triage in normal cycle

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.

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1.5/ 10 priority

Sources & remediation

Patch / fix
Exploit / PoC references
Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-345

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • debian_linux
  • exim
  • extra_packages_for_enterprise_linux
  • fedora

Threat summary

  • Patch or workaround signal is available
  • 1 mentions across 1 observed day

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 1 signal
  • 1 total mentions across 1 day

Affected systems

Vendors
debianeximfedoraproject
Products
debian_linuxeximextra_packages_for_enterprise_linuxfedora

6 versions affected across 4 products

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-06-05: 1Patch / Workaround · 2026-06-05: 1Technical Details · 2026-06-05: 106-05
Signal classification1 categories
Patch
1100.0%
Referenced assets1 URL
By indicator
Full discourse1 post
  • Ferramentas Linux@Cezar_H_Linux
    Patch

    Vulnerabilidade CVE-2023-51766 no Exim permite forjamento de e-mails. Guia completo para #Ubuntu: comandos de verificação, script de correção automática e mitigação temporária. Saiba mais: -&gt; https://tinyurl.com/4j6wy5rd https://t.co/yISPXZLKfG

    Post summary

    The tweet announces a guide for Ubuntu that includes verification commands, an automated fix script, and temporary mitigation for the Exim CVE‑2023‑51766 email‑forging vulnerability.

    1000049
    1.5K followersView on X
CPE platform detail7 entries

7 of 7 entries

PartVendorProductVersionTarget SWTarget HW
OSdebiandebian_linux10.0--
Appeximexim---
Appfedoraprojectextra_packages_for_enterprise_linux7.0--
Appfedoraprojectextra_packages_for_enterprise_linux8.0--
Appfedoraprojectextra_packages_for_enterprise_linux9.0--
OSfedoraprojectfedora38--
OSfedoraprojectfedora39--

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