CVE-2026-27852

An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No publicly available exploits are known.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-28 12:16

Updated : 2026-09-03 18:13

NVD link : CVE-2026-27852

Mitre link : CVE-2026-27852

CVE.ORG link : CVE-2026-27852

JSON object : View

Products Affected

No product.

CWE

CWE-400

Uncontrolled Resource Consumption

{"id": "CVE-2026-27852", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-27852", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-28T14:42:13.156866Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security@open-xchange.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@open-xchange.com", "affectedData": [{"vendor": "Open-Xchange GmbH", "modules": ["core"], "product": "OX Dovecot Pro", "versions": [{"status": "affected", "version": "2.3.0", "lessThan": "2.3.22.2", "versionType": "semver"}, {"status": "affected", "version": "3.0.0", "lessThan": "3.0.7", "versionType": "semver"}, {"status": "affected", "version": "3.1.0", "lessThan": "3.1.6", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Open-Xchange GmbH", "modules": ["core"], "product": "OX Dovecot CE", "versions": [{"status": "affected", "version": "2.3.0", "lessThan": "2.4.5", "versionType": "semver"}], "defaultStatus": "unaffected"}]}], "published": "2026-08-28T12:16:27.330", "references": [{"url": "https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json", "source": "security@open-xchange.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security@open-xchange.com", "description": [{"lang": "en", "value": "CWE-400"}]}], "descriptions": [{"lang": "en", "value": "An attacker that can send mail to a user can craft a message whose headers contain a very large number of email addresses or MIME parameters, which causes excessive memory usage when the message is later parsed. The message is still delivered, but reading it over IMAP can exhaust the memory limit of the process and terminate it, causing denial of service for the affected user. Update to non-vulnerable version. No publicly available exploits are known."}], "lastModified": "2026-09-03T18:13:44.643", "sourceIdentifier": "security@open-xchange.com"}