5.3

CVE-2026-27859: dovecot Uncontrolled Resource Consumption

CVSS: 5.3v3.1MediumAnalyzed
AliasesALPINE-CVE-2026-27859UBUNTU-CVE-2026-27859DEBIAN-CVE-2026-27859
Published 27-03-2026Last modified 27-03-2026
Open JSON

Vulnerability summary

CVE-2026-27859 is a medium (CVSS 5.3) Uncontrolled Resource Consumption vulnerability in dovecot. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.40%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 4 · Related 5
OPENSUSE-SU-2026:10442-1OPENSUSE-SU-2026:20554-1SUSE-SU-2026:21208-1SUSE-SU-2026:4139-1USN-8136-1

Timeline

  1. 27-03-2026
    PublishedVulnerability first disclosed.
  2. 27-03-2026
    Last modifiedVulnerability information updated.

Description

A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU. A suitably formatted mail message causes mail delivery process to consume large amounts of CPU time. Use MTA capabilities to limit RFC 2231 MIME parameters in mail messages, or upgrade to fixed version where the processing is limited. No publicly available exploits are known.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.40%

Chance of exploitation in the next 30 days

Percentile

33%

Versus all other CVEs

30-day change

+0.03 pp

From 0.37% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.40%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Alpine1 product
  • dovecot≥ 3.1.0, < 2.4.3-r0
Debian1 product
  • dovecot< 1:2.3.19.1+dfsg1-2.1+deb12u2 | < 1:2.4.1+dfsg1-6+deb13u4 | < 1:2.4.3+dfsg1-1
Dovecot1 product
Open-xchange1 product
  • dovecot< 3.0.5 | ≥ 3.1.0, < 3.1.4
Open-xchange gmbh1 product
Ubuntu1 product
  • dovecotAll versions (No fix recorded) | < 1:2.3.16+dfsg1-3ubuntu2.7 | < 1:2.3.21+dfsg1-2ubuntu6.3 | < 1:2.4.1+dfsg1-5ubuntu4.1

6 vendors · 6 products

References

6 links