Red Hat Security Advisory: dovecot security update
Dovecot is an IMAP server for Linux and other UNIX-like systems, written primarily with security in mind. It also contains a small POP3 server, and supports e-mail in either the maildir or mbox format. The SQL drivers and authentication plug-ins are provided as subpackages. Security Fix(es): * dovecot: ManageSieve: Denial of Service via crafted SASL initial response in AUTHENTICATE command (CVE-2025-59032) * dovecot: denial of service via crafted message before authentication (CVE-2026-27858) * dovecot: denial of service via specially crafted NOOP command (CVE-2026-27857) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
AI Analysis
Technical Summary
This advisory covers three denial of service vulnerabilities in Dovecot: CVE-2025-59032 involves a crafted SASL initial response in the AUTHENTICATE command affecting ManageSieve; CVE-2026-27858 involves a crafted message sent before authentication; and CVE-2026-27857 involves a specially crafted NOOP command. These vulnerabilities could cause denial of service conditions. Red Hat has issued an update for Dovecot packages in Red Hat Enterprise Linux 9 and associated variants to remediate these issues.
Potential Impact
Successful exploitation of these vulnerabilities could allow an attacker to cause denial of service conditions in the Dovecot service, potentially disrupting email access for users. There is no indication of privilege escalation, data disclosure, or code execution from the provided information.
Mitigation Recommendations
Red Hat has released updated Dovecot packages that fix these vulnerabilities. Users of Red Hat Enterprise Linux 9 and related products should apply the security update as described in Red Hat advisory RHSA-2026:13857. Patch status is confirmed as an official fix available from Red Hat. Refer to https://access.redhat.com/articles/11258 for update instructions.
Red Hat Security Advisory: dovecot security update
Description
Dovecot is an IMAP server for Linux and other UNIX-like systems, written primarily with security in mind. It also contains a small POP3 server, and supports e-mail in either the maildir or mbox format. The SQL drivers and authentication plug-ins are provided as subpackages. Security Fix(es): * dovecot: ManageSieve: Denial of Service via crafted SASL initial response in AUTHENTICATE command (CVE-2025-59032) * dovecot: denial of service via crafted message before authentication (CVE-2026-27858) * dovecot: denial of service via specially crafted NOOP command (CVE-2026-27857) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory covers three denial of service vulnerabilities in Dovecot: CVE-2025-59032 involves a crafted SASL initial response in the AUTHENTICATE command affecting ManageSieve; CVE-2026-27858 involves a crafted message sent before authentication; and CVE-2026-27857 involves a specially crafted NOOP command. These vulnerabilities could cause denial of service conditions. Red Hat has issued an update for Dovecot packages in Red Hat Enterprise Linux 9 and associated variants to remediate these issues.
Potential Impact
Successful exploitation of these vulnerabilities could allow an attacker to cause denial of service conditions in the Dovecot service, potentially disrupting email access for users. There is no indication of privilege escalation, data disclosure, or code execution from the provided information.
Mitigation Recommendations
Red Hat has released updated Dovecot packages that fix these vulnerabilities. Users of Red Hat Enterprise Linux 9 and related products should apply the security update as described in Red Hat advisory RHSA-2026:13857. Patch status is confirmed as an official fix available from Red Hat. Refer to https://access.redhat.com/articles/11258 for update instructions.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:13857
- Cve Count
- 3
- Additional Cves
- ["CVE-2026-27857","CVE-2026-27858"]
- Cvss Version
- null
Threat ID: 6a32cf7e9f87a2db092a947f
Added to database: 06/17/2026, 16:46:54 UTC
Last enriched: 06/26/2026, 01:10:33 UTC
Last updated: 08/01/2026, 07:17:57 UTC
Views: 48
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