Is CVE-2023-5770 actively exploited?

No active exploitation of CVE-2023-5770 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2023-5770 be exploited remotely?

Yes. CVE-2023-5770 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2023-5770?

CVE-2023-5770 has a CVSS score of 5.4 (MEDIUM).

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MEDIUM

CVE-2023-5770

CWE-838Published: January 9, 2024· Updated: Jun 17, 2026

5.4

CVSS v3.1

Official Description

Proofpoint Enterprise Protection contains a vulnerability in the email delivery agent that allows an unauthenticated attacker to inject improperly encoded HTML into the email body of a message through the email subject. The vulnerability is caused by inappropriate encoding when rewriting the email before delivery.This issue affects Proofpoint Enterprise Protection: from 8.20.2 before patch 4809, from 8.20.0 before patch 4805, from 8.18.6 before patch 4804 and all other prior versions.

NVD Source

Technical Analysis

CVE-2023-5770 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.