How severe is CVE-2020-18723?

CVE-2020-18723 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-18723 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-18723?

CVE-2020-18723 affects Altn Mdaemon Webmail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-18723?

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

When was CVE-2020-18723 published?

CVE-2020-18723 was published on 2021-02-03 and last updated on 2026-06-17.

CVE-2020-18723

CVE-2020-18723 is a medium-severity vulnerability in Altn Mdaemon Webmail with a CVSS 3.x base score of 5.4. 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 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Altn Mdaemon Webmail
Published: 2021-02-03
Last modified: 2026-06-17

Description

Stored cross-site scripting (XSS) in file attachment field in MDaemon webmail 19.5.5 allows an attacker to execute code on the email recipient side while forwarding an email to perform potentially malicious activities.

Frequently asked questions

What is CVE-2020-18723?: Stored cross-site scripting (XSS) in file attachment field in MDaemon webmail 19.5.5 allows an attacker to execute code on the email recipient side while forwarding an email to perform potentially malicious activities.
How severe is CVE-2020-18723?: CVE-2020-18723 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-18723 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-18723?: CVE-2020-18723 affects Altn Mdaemon Webmail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-18723?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-18723 published?: CVE-2020-18723 was published on 2021-02-03 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:altn:mdaemon_webmail:*:*:*:*:*:*:*:*

More vulnerabilities in Altn Mdaemon Webmail

CVE-2018-17792 — High (CVSS 8.8): MDaemon Webmail (formerly WorldClient) has CSRF.
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