Is CVE-2021-31988 actively exploited?

No active exploitation of CVE-2021-31988 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-31988 be exploited remotely?

Yes. CVE-2021-31988 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-31988?

CVE-2021-31988 has a CVSS score of 8.8 (HIGH).

HOME VULNERABILITIESCVE-2021-31988

HIGH

CVE-2021-31988

CWE-1286Published: October 5, 2021· Updated: Jun 17, 2026

8.8

CVSS v3.1

Official Description

A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to add the Carriage Return and Line Feed (CRLF) control characters and include arbitrary SMTP headers in the generated test email.

NVD Source

Technical Analysis

CVE-2021-31988 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.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.