Red Hat Security Advisory: dovecot security update
Multiple denial of service vulnerabilities have been identified in Dovecot, an IMAP and POP3 server for Linux and UNIX-like systems. These include a denial of service via a crafted SASL initial response in the AUTHENTICATE command (CVE-2025-59032), denial of service via a crafted message before authentication (CVE-2026-27858), and denial of service via a specially crafted NOOP command (CVE-2026-27857). Red Hat has issued an important security advisory addressing these issues with updates available for affected Red Hat Enterprise Linux 8.4 versions.
AI Analysis
Technical Summary
Dovecot contains multiple denial of service vulnerabilities: CVE-2025-59032 involves the ManageSieve component where a crafted SASL initial response in the AUTHENTICATE command can cause denial of service; CVE-2026-27858 allows denial of service via a crafted message before authentication; and CVE-2026-27857 involves denial of service via a specially crafted NOOP command. These vulnerabilities affect Red Hat Enterprise Linux 8.4 Extended Update Support and Advanced Update Support versions. Red Hat has released security updates to address these issues as detailed in advisory RHSA-2026:19455.
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting mail services. There is no indication of code execution or data compromise. The impact is limited to service availability.
Mitigation Recommendations
Red Hat has released security updates for Dovecot in Red Hat Enterprise Linux 8.4 Extended Update Support and Advanced Update Support. Users should apply the updates referenced in advisory RHSA-2026:19455 to remediate these denial of service vulnerabilities. For update instructions, refer to https://access.redhat.com/articles/11258. No additional mitigation steps are indicated by the vendor.
Red Hat Security Advisory: dovecot security update
Description
Multiple denial of service vulnerabilities have been identified in Dovecot, an IMAP and POP3 server for Linux and UNIX-like systems. These include a denial of service via a crafted SASL initial response in the AUTHENTICATE command (CVE-2025-59032), denial of service via a crafted message before authentication (CVE-2026-27858), and denial of service via a specially crafted NOOP command (CVE-2026-27857). Red Hat has issued an important security advisory addressing these issues with updates available for affected Red Hat Enterprise Linux 8.4 versions.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Dovecot contains multiple denial of service vulnerabilities: CVE-2025-59032 involves the ManageSieve component where a crafted SASL initial response in the AUTHENTICATE command can cause denial of service; CVE-2026-27858 allows denial of service via a crafted message before authentication; and CVE-2026-27857 involves denial of service via a specially crafted NOOP command. These vulnerabilities affect Red Hat Enterprise Linux 8.4 Extended Update Support and Advanced Update Support versions. Red Hat has released security updates to address these issues as detailed in advisory RHSA-2026:19455.
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting mail services. There is no indication of code execution or data compromise. The impact is limited to service availability.
Mitigation Recommendations
Red Hat has released security updates for Dovecot in Red Hat Enterprise Linux 8.4 Extended Update Support and Advanced Update Support. Users should apply the updates referenced in advisory RHSA-2026:19455 to remediate these denial of service vulnerabilities. For update instructions, refer to https://access.redhat.com/articles/11258. No additional mitigation steps are indicated by the vendor.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:19455
- Cve Count
- 3
- Additional Cves
- ["CVE-2026-27857","CVE-2026-27858"]
- Cvss Version
- null
Threat ID: 6a32cf799f87a2db092a8e14
Added to database: 6/17/2026, 4:46:49 PM
Last enriched: 6/17/2026, 5:05:33 PM
Last updated: 6/17/2026, 6:24:35 PM
Views: 2
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