Red Hat Security Advisory: dovecot security update
Multiple denial of service vulnerabilities have been identified in Dovecot, an IMAP and POP3 server for UNIX-like systems. These include issues in ManageSieve via a crafted SASL initial response in the AUTHENTICATE command, denial of service via crafted messages before authentication, and denial of service via a specially crafted NOOP command. Red Hat has released an important security update addressing these issues in Red Hat Enterprise Linux 9.6 Extended Update Support. The vulnerabilities affect various architectures supported by Red Hat Enterprise Linux 9.6. No CVSS scores are provided in the advisory.
AI Analysis
Technical Summary
This advisory addresses three denial of service vulnerabilities in Dovecot: CVE-2025-59032 involves ManageSieve where a crafted SASL initial response in the AUTHENTICATE command can cause denial of service; CVE-2026-27858 involves denial of service via a crafted message before authentication; CVE-2026-27857 involves denial of service via a specially crafted NOOP command. Red Hat has issued updates for Red Hat Enterprise Linux 9.6 Extended Update Support to remediate these issues. The advisory does not provide CVSS scores but rates the impact as Important (high).
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting email services. The issues affect the ManageSieve component and core IMAP/POP3 functionality before authentication and via NOOP commands. There are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released updated Dovecot packages for Red Hat Enterprise Linux 9.6 Extended Update Support that address these vulnerabilities. Users should apply the provided security updates as described in the Red Hat advisory RHSA-2026:17626 and the referenced article https://access.redhat.com/articles/11258. No alternative mitigations or workarounds are specified. Patch status is confirmed as fixed in the updated packages.
Red Hat Security Advisory: dovecot security update
Description
Multiple denial of service vulnerabilities have been identified in Dovecot, an IMAP and POP3 server for UNIX-like systems. These include issues in ManageSieve via a crafted SASL initial response in the AUTHENTICATE command, denial of service via crafted messages before authentication, and denial of service via a specially crafted NOOP command. Red Hat has released an important security update addressing these issues in Red Hat Enterprise Linux 9.6 Extended Update Support. The vulnerabilities affect various architectures supported by Red Hat Enterprise Linux 9.6. No CVSS scores are provided in the advisory.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This advisory addresses three denial of service vulnerabilities in Dovecot: CVE-2025-59032 involves ManageSieve where a crafted SASL initial response in the AUTHENTICATE command can cause denial of service; CVE-2026-27858 involves denial of service via a crafted message before authentication; CVE-2026-27857 involves denial of service via a specially crafted NOOP command. Red Hat has issued updates for Red Hat Enterprise Linux 9.6 Extended Update Support to remediate these issues. The advisory does not provide CVSS scores but rates the impact as Important (high).
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting email services. The issues affect the ManageSieve component and core IMAP/POP3 functionality before authentication and via NOOP commands. There are no known exploits in the wild at this time.
Mitigation Recommendations
Red Hat has released updated Dovecot packages for Red Hat Enterprise Linux 9.6 Extended Update Support that address these vulnerabilities. Users should apply the provided security updates as described in the Red Hat advisory RHSA-2026:17626 and the referenced article https://access.redhat.com/articles/11258. No alternative mitigations or workarounds are specified. Patch status is confirmed as fixed in the updated packages.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:17626
- Cve Count
- 3
- Additional Cves
- ["CVE-2026-27857","CVE-2026-27858"]
- Cvss Version
- null
Threat ID: 6a32cf7e9f87a2db092a9444
Added to database: 6/17/2026, 4:46:54 PM
Last enriched: 6/17/2026, 4:51:11 PM
Last updated: 6/17/2026, 6:23:14 PM
Views: 2
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