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 triggered by a crafted SASL initial response in the AUTHENTICATE command (CVE-2025-59032), a crafted message before authentication (CVE-2026-27858), and a specially crafted NOOP command (CVE-2026-27857). Red Hat has released security updates addressing these vulnerabilities in Red Hat Enterprise Linux 9 and related variants. The update is rated as Important by Red Hat Product Security.
AI Analysis
Technical Summary
Dovecot contains three denial of service vulnerabilities: CVE-2025-59032 allows denial of service via a crafted SASL initial response in the AUTHENTICATE command of ManageSieve; CVE-2026-27858 allows denial of service via a crafted message before authentication; and CVE-2026-27857 allows denial of service via a specially crafted NOOP command. These vulnerabilities affect Red Hat Enterprise Linux 9 and related distributions. Red Hat has issued an update (RHSA-2026:19364) that fixes these issues by patching the affected packages to version 2.3.16-18.el9_8. The advisory rates the impact as Important and provides updated packages for multiple architectures and variants.
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting email services. There is no indication of code execution or data compromise. The impact is limited to service availability.
Mitigation Recommendations
Red Hat has released an official security update (RHSA-2026:19364) that addresses these vulnerabilities. Users should apply the updated Dovecot packages (version 2.3.16-18.el9_8) available for Red Hat Enterprise Linux 9 and its variants as detailed in the advisory. Patch status is confirmed by the vendor advisory. No additional mitigation steps are specified beyond applying the update.
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 triggered by a crafted SASL initial response in the AUTHENTICATE command (CVE-2025-59032), a crafted message before authentication (CVE-2026-27858), and a specially crafted NOOP command (CVE-2026-27857). Red Hat has released security updates addressing these vulnerabilities in Red Hat Enterprise Linux 9 and related variants. The update is rated as Important by Red Hat Product Security.
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Dovecot contains three denial of service vulnerabilities: CVE-2025-59032 allows denial of service via a crafted SASL initial response in the AUTHENTICATE command of ManageSieve; CVE-2026-27858 allows denial of service via a crafted message before authentication; and CVE-2026-27857 allows denial of service via a specially crafted NOOP command. These vulnerabilities affect Red Hat Enterprise Linux 9 and related distributions. Red Hat has issued an update (RHSA-2026:19364) that fixes these issues by patching the affected packages to version 2.3.16-18.el9_8. The advisory rates the impact as Important and provides updated packages for multiple architectures and variants.
Potential Impact
Successful exploitation of these vulnerabilities can cause denial of service conditions in the Dovecot server, potentially disrupting email services. There is no indication of code execution or data compromise. The impact is limited to service availability.
Mitigation Recommendations
Red Hat has released an official security update (RHSA-2026:19364) that addresses these vulnerabilities. Users should apply the updated Dovecot packages (version 2.3.16-18.el9_8) available for Red Hat Enterprise Linux 9 and its variants as detailed in the advisory. Patch status is confirmed by the vendor advisory. No additional mitigation steps are specified beyond applying the update.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:19364
- Cve Count
- 3
- Additional Cves
- ["CVE-2026-27857","CVE-2026-27858"]
- Cvss Version
- null
Threat ID: 6a32cf799f87a2db092a8e24
Added to database: 6/17/2026, 4:46:49 PM
Last enriched: 6/17/2026, 5:05:20 PM
Last updated: 6/17/2026, 7:24:29 PM
Views: 4
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.