CVE-2023-22278: m-FILTER prior to Ver.5.70R01 (Ver.5 Series) and m-FILTER prior to Ver.4.87R04 (Ver.4 Series) allows a remote unauthe…

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 6 Jan 2023. It cites 1 public report, the first from 6 Jan 2023.

• jvn.jp

How likely is exploitation in the next 30 days?

0.7%

EPSS score, percentile 54 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

5.3 Medium

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• m-FILTER prior to Ver.5.70R01 (Ver.5 Series) and m-FILTER prior to Ver.4.87R04…

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

m-FILTER prior to Ver.5.70R01 (Ver.5 Series) and m-FILTER prior to Ver.4.87R04 (Ver.4 Series) allows a remote unauthenticated attacker to bypass authentication and send users' unintended email when email is being sent under the certain conditions. The attacks exploiting this vulnerability have been observed.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline