How severe is CVE-2020-3811?

CVE-2020-3811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2020-3811 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3811?

CVE-2020-3811 primarily affects Debian Debian Linux. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-3811?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-3811 published?

CVE-2020-3811 was published on 2020-05-26 and last updated on 2026-06-17.

CVE-2020-3811

CVE-2020-3811 is a high-severity vulnerability in Debian Debian Linux with a CVSS 3.x base score of 7.5. 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-665.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-665
Affected product: Debian Debian Linux
Published: 2020-05-26
Last modified: 2026-06-17

Description

qmail-verify as used in netqmail 1.06 is prone to a mail-address verification bypass vulnerability.

Frequently asked questions

What is CVE-2020-3811?: qmail-verify as used in netqmail 1.06 is prone to a mail-address verification bypass vulnerability.
How severe is CVE-2020-3811?: CVE-2020-3811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2020-3811 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3811?: CVE-2020-3811 primarily affects Debian Debian Linux. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-3811?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-3811 published?: CVE-2020-3811 was published on 2020-05-26 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:netqmail:netqmail:1.06:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*

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