How severe is CVE-2021-20723?

CVE-2021-20723 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2021-20723 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20723?

CVE-2021-20723 affects Mailform01 Project Mailform01. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20723?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20723 published?

CVE-2021-20723 was published on 2021-05-24 and last updated on 2026-06-17.

CVE-2021-20723

CVE-2021-20723 is a medium-severity vulnerability in Mailform01 Project Mailform01 with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mailform01 Project Mailform01
Published: 2021-05-24
Last modified: 2026-06-17

Description

Reflected cross-site scripting vulnerability in [MailForm01] free edition (versions which the last updated date listed at the top of descriptions in the program file is from 2014 December 12 to 2018 July 27) allows a remote attacker to inject an arbitrary script via unspecified vectors.

Frequently asked questions

What is CVE-2021-20723?: Reflected cross-site scripting vulnerability in [MailForm01] free edition (versions which the last updated date listed at the top of descriptions in the program file is from 2014 December 12 to 2018 July 27) allows a remote attacker to inject an arbitrary script via unspecified vectors.
How severe is CVE-2021-20723?: CVE-2021-20723 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2021-20723 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20723?: CVE-2021-20723 affects Mailform01 Project Mailform01. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20723?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20723 published?: CVE-2021-20723 was published on 2021-05-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mailform01_project:mailform01:*:*:*:*:free:*:*:*

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