{ "document": { "acknowledgments": [ { "names": [ "Anonymous" ] }, { "names": [ "Anonymous" ] } ], "aggregate_severity": { "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system", "text": "Important" }, "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "text": "Public", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en-US", "notes": [ { "category": "general", "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle", "title": "Additional Resources" }, { "category": "legal_disclaimer", "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.", "title": "Disclaimer" }, { "category": "general", "text": "Required. The vulnerability documented by this CVE requires customer action to resolve.", "title": "Customer Action" } ], "publisher": { "category": "vendor", "contact_details": "secure@microsoft.com", "name": "Microsoft Security Response Center", "namespace": "https://msrc.microsoft.com" }, "references": [ { "category": "self", "summary": "CVE-2026-55007 Microsoft Exchange Server Remote Code Execution Vulnerability - HTML", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007" }, { "category": "self", "summary": "CVE-2026-55007 Microsoft Exchange Server Remote Code Execution Vulnerability - CSAF", "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-55007.json" }, { "category": "external", "summary": "Microsoft Exploitability Index", "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1" }, { "category": "external", "summary": "Microsoft Support Lifecycle", "url": "https://support.microsoft.com/lifecycle" }, { "category": "external", "summary": "Common Vulnerability Scoring System", "url": "https://www.first.org/cvss" } ], "title": "Microsoft Exchange Server Remote Code Execution Vulnerability", "tracking": { "current_release_date": "2026-09-08T07:00:00.000Z", "generator": { "date": "2026-10-16T15:07:51.194Z", "engine": { "name": "MSRC Generator", "version": "1.0" } }, "id": "msrc_CVE-2026-55007", "initial_release_date": "2026-09-08T07:00:00.000Z", "revision_history": [ { "date": "2026-09-08T07:00:00.000Z", "legacy_version": "1", "number": "1", "summary": "Information published." } ], "status": "final", "version": "1" } }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_version_range", "name": "<15.02.1544.046", "product": { "name": "Microsoft Exchange Server 2019 Cumulative Update 14 <15.02.1544.046", "product_id": "3" } }, { "category": "product_version", "name": "15.02.1544.046", "product": { "name": "Microsoft Exchange Server 2019 Cumulative Update 14 15.02.1544.046", "product_id": "12293" } } ], "category": "product_name", "name": "Microsoft Exchange Server 2019 Cumulative Update 14" }, { "branches": [ { "category": "product_version_range", "name": "<15.02.1748.051", "product": { "name": "Microsoft Exchange Server 2019 Cumulative Update 15 <15.02.1748.051", "product_id": "2" } }, { "category": "product_version", "name": "15.02.1748.051", "product": { "name": "Microsoft Exchange Server 2019 Cumulative Update 15 15.02.1748.051", "product_id": "12502" } } ], "category": "product_name", "name": "Microsoft Exchange Server 2019 Cumulative Update 15" }, { "branches": [ { "category": "product_version_range", "name": "<15.02.2562.049", "product": { "name": "Microsoft Exchange Server Subscription Edition RTM <15.02.2562.049", "product_id": "1" } }, { "category": "product_version", "name": "15.02.2562.049", "product": { "name": "Microsoft Exchange Server Subscription Edition RTM 15.02.2562.049", "product_id": "16792" } } ], "category": "product_name", "name": "Microsoft Exchange Server Subscription Edition RTM" } ], "category": "vendor", "name": "Microsoft" } ] }, "vulnerabilities": [ { "cve": "CVE-2026-55007", "cwe": { "id": "CWE-415", "name": "Double Free" }, "notes": [ { "category": "general", "text": "Microsoft", "title": "Assigning CNA" }, { "category": "faq", "text": "An unauthenticated attacker could send a specially crafted Visio attachment to an affected Exchange server. The server could process the attachment during content indexing, and successful exploitation could allow the attacker to execute code on the server. User interaction is not required.", "title": "How could an attacker exploit this vulnerability?" }, { "category": "faq", "text": "Successful exploitation requires the target system to be under sustained low-memory (memory pressure) conditions, which are not commonly present in normal operation. This makes the vulnerability difficult to reliably trigger, as the attacker must first induce or wait for a constrained memory state before exploitation becomes possible.", "title": "According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?" } ], "product_status": { "fixed": [ "12293", "12502", "16792" ], "known_affected": [ "1", "2", "3" ] }, "references": [ { "category": "self", "summary": "CVE-2026-55007 Microsoft Exchange Server Remote Code Execution Vulnerability - HTML", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55007" }, { "category": "self", "summary": "CVE-2026-55007 Microsoft Exchange Server Remote Code Execution Vulnerability - CSAF", "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-55007.json" } ], "remediations": [ { "category": "vendor_fix", "date": "2026-09-08T07:00:00.000Z", "details": "15.02.1544.046:Security Update:https://support.microsoft.com/help/5121610", "product_ids": [ "3" ], "url": "https://support.microsoft.com/help/5121610" }, { "category": "vendor_fix", "date": "2026-09-08T07:00:00.000Z", "details": "15.02.1748.051:Security Update:https://support.microsoft.com/help/5121609", "product_ids": [ "2" ], "url": "https://support.microsoft.com/help/5121609" }, { "category": "vendor_fix", "date": "2026-09-08T07:00:00.000Z", "details": "15.02.2562.049:Security Update:https://support.microsoft.com/help/5121608", "product_ids": [ "1" ], "url": "https://support.microsoft.com/help/5121608" } ], "scores": [ { "cvss_v3": { "attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "exploitCodeMaturity": "UNPROVEN", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "remediationLevel": "OFFICIAL_FIX", "reportConfidence": "CONFIRMED", "scope": "UNCHANGED", "temporalScore": 7.1, "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C", "version": "3.1" }, "products": [ "1", "2", "3" ] } ], "threats": [ { "category": "impact", "details": "Remote Code Execution" }, { "category": "exploit_status", "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely" } ], "title": "Microsoft Exchange Server Remote Code Execution Vulnerability" } ] }