How severe is CVE-2020-7957?

CVE-2020-7957 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2020-7957 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-7957?

CVE-2020-7957 primarily affects Dovecot. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-7957?

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

When was CVE-2020-7957 published?

CVE-2020-7957 was published on 2020-02-12 and last updated on 2026-06-17.

CVE-2020-7957

CVE-2020-7957 is a medium-severity vulnerability in Dovecot with a CVSS 3.x base score of 5.3. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Dovecot
Published: 2020-02-12
Last modified: 2026-06-17

Description

The IMAP and LMTP components in Dovecot 2.3.9 before 2.3.9.3 mishandle snippet generation when many characters must be read to compute the snippet and a trailing > character exists. This causes a denial of service in which the recipient cannot read all of their messages.

Frequently asked questions

What is CVE-2020-7957?: The IMAP and LMTP components in Dovecot 2.3.9 before 2.3.9.3 mishandle snippet generation when many characters must be read to compute the snippet and a trailing > character exists. This causes a denial of service in which the recipient cannot read all of their messages.
How severe is CVE-2020-7957?: CVE-2020-7957 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2020-7957 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-7957?: CVE-2020-7957 primarily affects Dovecot. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-7957?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-7957 published?: CVE-2020-7957 was published on 2020-02-12 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:dovecot:dovecot:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*

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