CVE-2026-27852: open-xchange gmbh ox dovecot ce Uncontrolled Resource Consumption
Vulnerability summary
CVE-2026-27852 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in open-xchange gmbh ox dovecot ce. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.1% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 9 · Related 5Timeline
- 28-08-2026PublishedVulnerability first disclosed.
- 28-08-2026Last modifiedVulnerability information updated.
Description
An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No publicly available exploits are known.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.43%
Chance of exploitation in the next 30 days
Percentile
36%
Versus all other CVEs
30-day change
+0.07 pp
From 0.36% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Open-xchange gmbh2 products
- ox dovecot ce≥ 2.3.0, < 2.4.5
- ox dovecot pro≥ 2.3.0, < 2.3.22.2 | ≥ 3.0.0, < 3.0.7 | ≥ 3.1.0, < 3.1.6
Alpine1 product
- dovecot< 2.4.5-r0
Debian1 product
- dovecotAll versions (No fix recorded) | < 1:2.4.1+dfsg1-6+deb13u7 | < 1:2.4.5+dfsg1-1
Ubuntu1 product
- dovecotAll versions (No fix recorded)
4 vendors · 5 products
