{
  "document": {
    "aggregate_severity": {
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "TuxCare License Agreement",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
        "title": "Terms of Use"
      },
      {
        "category": "details",
        "text": "CVE-2026-27857: limit the number of open IMAP parser lists in imap-login\n  to prevent excessive memory usage from deeply nested parentheses (e.g. NOOP\n  (((...))))",
        "title": "Details"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://tuxcare.com/contact/",
      "name": "TuxCare",
      "namespace": "https://tuxcare.com/"
    },
    "references": [
      {
        "category": "self",
        "summary": "https://cve.tuxcare.com/els/releases/CLSA-2026:1777977059",
        "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1777977059"
      },
      {
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        "summary": "Canonical URL",
        "url": "https://security.tuxcare.com/csaf/v2/els_os/centos-stream8els/advisories/2026/clsa-2026_1777977059.json"
      }
    ],
    "tracking": {
      "current_release_date": "2026-05-05T10:31:53Z",
      "generator": {
        "date": "2026-05-05T10:31:53Z",
        "engine": {
          "name": "pyCSAF"
        }
      },
      "id": "CLSA-2026:1777977059",
      "initial_release_date": "2026-05-05T10:31:53Z",
      "revision_history": [
        {
          "date": "2026-05-05T10:31:53Z",
          "number": "1",
          "summary": "Initial version"
        }
      ],
      "status": "final",
      "version": "1"
    },
    "title": "dovecot: Fix of CVE-2026-27857"
  },
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        "category": "vendor",
        "name": "Red Hat, Inc."
      },
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  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-27857",
      "cwe": {
        "id": "CWE-400",
        "name": "Uncontrolled Resource Consumption"
      },
      "notes": [
        {
          "category": "description",
          "text": "Sending \"NOOP (((...)))\" command with 4000 parenthesis open+close results in ~1MB extra memory usage. Longer commands will result in client disconnection. This 1 MB can be left allocated for longer time periods by not sending the command ending LF. So attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Attacker could connect possibly from even a single IP and create 1000 connections to allocate 1 GB of memory, which would likely result in reaching VSZ limit and killing the process and its other proxied connections. Install fixed version, there is no other remediation. No publicly available exploits are known.",
          "title": "Vulnerability description"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        }
      ],
      "product_status": {
        "fixed": [
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          "CentOS-Stream-8:dovecot-1:2.3.16-5.el8.tuxcare.els1.x86_64",
          "CentOS-Stream-8:dovecot-devel-1:2.3.16-5.el8.tuxcare.els1.i686",
          "CentOS-Stream-8:dovecot-devel-1:2.3.16-5.el8.tuxcare.els1.x86_64",
          "CentOS-Stream-8:dovecot-mysql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
          "CentOS-Stream-8:dovecot-pgsql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
          "CentOS-Stream-8:dovecot-pigeonhole-1:2.3.16-5.el8.tuxcare.els1.x86_64"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-27857"
        },
        {
          "category": "external",
          "summary": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json",
          "url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0001.json"
        }
      ],
      "release_date": "2026-03-27T09:16:00Z",
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-05-05T10:31:04.207700Z",
          "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1777977059",
          "product_ids": [
            "CentOS-Stream-8:dovecot-1:2.3.16-5.el8.tuxcare.els1.i686",
            "CentOS-Stream-8:dovecot-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-devel-1:2.3.16-5.el8.tuxcare.els1.i686",
            "CentOS-Stream-8:dovecot-devel-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-mysql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-pgsql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-pigeonhole-1:2.3.16-5.el8.tuxcare.els1.x86_64"
          ],
          "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1777977059"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "CentOS-Stream-8:dovecot-1:2.3.16-5.el8.tuxcare.els1.i686",
            "CentOS-Stream-8:dovecot-1:2.3.16-5.el8.tuxcare.els1.x86_64",
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            "CentOS-Stream-8:dovecot-mysql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-pgsql-1:2.3.16-5.el8.tuxcare.els1.x86_64",
            "CentOS-Stream-8:dovecot-pigeonhole-1:2.3.16-5.el8.tuxcare.els1.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Important"
        }
      ]
    }
  ]
}