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Medium 5.3Published Mar 27, 2026

CVE-2025-59028When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail.

Updated under an hour ago ()

Does this affect you?

It affects Open-Xchange GmbH OX Dovecot Pro and 2 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
CWE-20
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
OX
NVD analysis
Analyzed
Record last updated
Mar 27, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Open-Xchange GmbH OX Dovecot Pro
open_xchange:ox_dovecot_pro (from the name)
through 3.1.0; through 2.4.0
CNA record
dovecot dovecot
dovecot:dovecot
before 2.4.3
NVD
open-xchange dovecot
open-xchange:dovecot
before 3.1.2
NVD

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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