What is CVE-2020-28200?

CVE-2020-28200 is a medium-severity vulnerability in Dovecot, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2021-06-28.

How severe is CVE-2020-28200?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Resource exhaustion in Dovecot

CVE-2020-28200

The Sieve engine in Dovecot before 2.3.15 allows Uncontrolled Resource Consumption, as demonstrated by a situation with a complex regular expression for the regex extension.

Published 2021-06-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.020 (79.7th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 79.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.020 · newest: 0.020 · change: 0.000

Affected products

Dovecot
Fedoraproject Fedora — versions 33, 34

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

dovecot.org/security (Vendor Advisory)
www.openwall.com/lists/oss-security/2021/06/28/3 (Mailing List, Third Party Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)

Frequently asked questions

What is CVE-2020-28200?: CVE-2020-28200 is a medium-severity vulnerability in Dovecot, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2021-06-28.
How severe is CVE-2020-28200?: Medium severity. CVSS v3 base score is 4.3 out of 10.