Dovecot Vulnerabilities Lead to Denial of Service Risks in Ubuntu and Debian

Severity: Medium (Score: 57.8)

Sources: Ubuntu, Linuxsecurity

Summary

Recent updates to Dovecot have revealed multiple vulnerabilities affecting Ubuntu and Debian systems. Specifically, CVE-2025-59031 and CVE-2025-59032 expose systems to denial of service attacks through mishandling of zip files and AUTHENTICATE commands, respectively. Ubuntu 22.04 LTS and 24.04 LTS were affected by a regression from a prior fix, while Debian's Dovecot was found to have unsafe handling of zip-style attachments. The vulnerabilities allow attackers to exploit these flaws to cause service disruptions or potentially access sensitive information. Affected versions include Dovecot on Ubuntu 25.10 and Debian systems using the vulnerable scripts. Patches have been released to address these issues. Security professionals are advised to apply updates promptly to mitigate risks. Key Points: • Dovecot vulnerabilities allow denial of service and potential information exposure. • Ubuntu 22.04 LTS and 24.04 LTS experienced a regression from a previous update. • Debian has removed the unsafe decode2text.sh script to prevent exploitation.

Key Entities

• Denial of Service (attack_type)
• CVE-2025-59028 (cve)
• CVE-2025-59031 (cve)
• CVE-2025-59032 (cve)
• CVE-2026-0394 (cve)
• CVE-2026-24031 (cve)
• CWE-22 - Path Traversal (cwe)
• CWE-287 - Improper Authentication (cwe)
• Cwe-89 - SQL Injection (cwe)
• Debian (company)
• Dovecot (platform)