CVE-2021-31987

Name: CVE-2021-31987
Creator: NVD / NIST
Published: 2021-10-05T22:15:07.887+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.86%

Last modified Jun 17, 2026

CVE-2021-31987 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to bypass blocked network recipients.. EPSS estimates a 0.86% chance of exploitation in the next 30 days.

Description

A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to bypass blocked network recipients.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

0.86%

54.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-1286

Affected Software

Vendor	Product	Versions
Axis	Axis Os	< 10.8
Axis	Axis Os 2016	< 6.50.5.5
Axis	Axis Os 2018	< 8.40.4.3
Axis	Axis Os 2020	< 9.80.3.5

References

https://www.axis.com/files/tech_notes/CVE-2021-31987.pdfVendor Advisory
https://www.axis.com/files/tech_notes/CVE-2021-31987.pdfVendor Advisory

Timeline

Published: Oct 5, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31987?

A user controlled parameter related to SMTP test functionality is not correctly validated making it possible to bypass blocked network recipients.

How severe is CVE-2021-31987?

CVE-2021-31987 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.86% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31987?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31987?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST