CVE-2026-55007

Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

CVSS v3 8.1 HIGH

8.1^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_14::::::
	cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_15::::::
	cpe:2.3:a:microsoft:exchange_server_subscription_edition::::::::

History

05 Oct 2026, 17:11

Type	Values Removed	Values Added
References	~~() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007 -~~	() https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007 - Patch, Vendor Advisory
CPE		cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_15:::::: cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_14:::::: cpe:2.3:a:microsoft:exchange_server_subscription_edition::::::::
First Time		Microsoft exchange Server Subscription Edition Microsoft exchange Server Microsoft

Information

Published : 2026-09-08 18:17

Updated : 2026-10-05 17:11

NVD link : CVE-2026-55007

Mitre link : CVE-2026-55007

CVE.ORG link : CVE-2026-55007

JSON object : View

Products Affected

microsoft

exchange_server
exchange_server_subscription_edition

CWE

CWE-415

Double Free

{"id": "CVE-2026-55007", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55007", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-09T04:20:19.366481Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "secure@microsoft.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.2}]}, "affected": [{"source": "secure@microsoft.com", "affectedData": [{"vendor": "Microsoft", "product": "Microsoft Exchange Server 2019 Cumulative Update 14", "versions": [{"status": "affected", "version": "15.02.0.0", "lessThan": "15.02.1544.046", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft Exchange Server 2019 Cumulative Update 15", "versions": [{"status": "affected", "version": "15.02.0.0", "lessThan": "15.02.1748.051", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft Exchange Server Subscription Edition RTM", "versions": [{"status": "affected", "version": "15.02.0.0", "lessThan": "15.02.2562.049", "versionType": "custom"}], "platforms": ["x64-based Systems"]}]}], "published": "2026-09-08T18:17:41.820", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007", "tags": ["Patch", "Vendor Advisory"], "source": "secure@microsoft.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "secure@microsoft.com", "description": [{"lang": "en", "value": "CWE-415"}]}], "descriptions": [{"lang": "en", "value": "Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network."}], "lastModified": "2026-10-05T17:11:46.140", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_14:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8C98993B-82A5-48CC-947F-896CEA0CDB7F"}, {"criteria": "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_15:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7166BCE0-1D55-46B2-96B9-250AB4BB6291"}, {"criteria": "cpe:2.3:a:microsoft:exchange_server_subscription_edition:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DFE6E02B-98D8-4797-B4CB-E48E2F193344", "versionEndExcluding": "15.02.2562.049"}], "operator": "OR"}]}], "sourceIdentifier": "secure@microsoft.com"}