CVE-2025-59028 | BDVDB-2026-323294 Detail

Open-XchangeOX Dovecot Pro

Description#

When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail. Invalid BASE64 data can be used to DoS a vulnerable server to break concurrent logins. Install fixed version or disable concurrency in login processes (heavy perfomance penalty on large deployments). No publicly available exploits are known.

Impact#

Per CVSS v3.1: confidentiality impact none, integrity impact none, availability impact low. Attack vector: network.

Weaknesses#

CWE-20 Improper Input Validation

References#

https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json

Exploit#

No public exploit known

History#

Version 12026-03-27Record published in the CVE List.

Published

Published: 2026-03-27
Last modified: 2026-03-27

Vendor information

Vendor: Open-Xchange
Product: OX Dovecot Pro

All Open-Xchange vulnerabilities

Score

5.3 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 40.5.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Improper Input Validation

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
<= 3.1.0
Fixed
Not stated
Vulnerable
<= 2.4.0
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

5.3 Medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User Interaction	None
Scope	Unchanged
Confidentiality	None
Integrity	None
Availability	Low

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).