# Microsoft Exchange Server Subscription Edition vulnerabilities Source: https://junglewise.ai/threats/technologies/exchange-server-subscription-edition Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats Updated: 13 November 2026, 03:07 UTC. Rebuilt every hour. Data: https://junglewise.ai/threats/technologies/exchange-server-subscription-edition.json License: CC BY 4.0 with a link back Junglewise Threat Intelligence has tracked 9 vulnerabilities in Microsoft Exchange Server Subscription Edition: 0 in the last 7 days and 3 in the last 90 days, 1 of them critical and 0 exploited in the wild. The most recent, CVE-2026-87696, was published on 13 October 2026. 3 vulnerabilities in the last four weeks, up from none in the four before. ## Counts - Last 7 days: 0 - Last 30 days: 0 - Last 90 days: 3 - All time: 9 (1 critical, 0 exploited in the wild) ## About Microsoft Exchange Server Subscription Edition A subscription-based version of the Microsoft Exchange Server email and calendaring platform. ## Latest Microsoft Exchange Server Subscription Edition vulnerabilities - [CVE-2026-87696: Microsoft Exchange Server cryptographic signature verification privilege escalation](https://junglewise.ai/threats/cve-2026-87696-improper-verification-of-cryptographic-signature-in-microsoft) (high, CVSS 7.5, published 13 Oct 2026) - [CVE-2026-87695: Microsoft Exchange Server privilege escalation via untrusted control sphere](https://junglewise.ai/threats/cve-2026-87695-inclusion-of-functionality-from-untrusted-control-sphere-in) (high, CVSS 7.8, published 13 Oct 2026) - [CVE-2026-87692: Microsoft Exchange Server deserialization privilege elevation](https://junglewise.ai/threats/cve-2026-87692-deserialization-of-untrusted-data-in-microsoft-exchange-server) (high, CVSS 7.8, published 13 Oct 2026) - [CVE-2026-62911: Microsoft Exchange Server privilege escalation via NTLM relay to MRSProxy](https://junglewise.ai/threats/cve-2026-62911-microsoft-exchange-server-privilege-escalation-via-ntlm-relay-to) (high, CVSS 8, published 11 Aug 2026) - [CVE-2026-55009: Microsoft Exchange Server deserialization privilege escalation](https://junglewise.ai/threats/cve-2026-55009-microsoft-exchange-server-deserialization-privilege-escalation) (high, CVSS 7.8, published 14 Jul 2026) - [CVE-2026-55008: Microsoft Exchange Server cross-site scripting spoofing vulnerability](https://junglewise.ai/threats/cve-2026-55008-microsoft-exchange-server-cross-site-scripting-spoofing) (critical, CVSS 9.6, published 14 Jul 2026) - [CVE-2026-55005: Microsoft Exchange Server heap overflow remote code execution](https://junglewise.ai/threats/cve-2026-55005-microsoft-exchange-server-heap-overflow-remote-code-execution) (high, CVSS 8.8, published 14 Jul 2026) - [CVE-2026-21527: Microsoft Exchange Server UI misrepresentation spoofing vulnerability](https://junglewise.ai/threats/cve-2026-21527-microsoft-exchange-server-ui-misrepresentation-spoofing) (medium, CVSS 6.5, published 10 Feb 2026) - [CVE-2025-53786: Microsoft Exchange Server improper authentication in hybrid deployments](https://junglewise.ai/threats/cve-2025-53786-microsoft-exchange-server-improper-authentication-in-hybrid) (high, CVSS 8, published 6 Aug 2025) ## Most severe Microsoft Exchange Server Subscription Edition vulnerabilities - [CVE-2026-55008: Microsoft Exchange Server cross-site scripting spoofing vulnerability](https://junglewise.ai/threats/cve-2026-55008-microsoft-exchange-server-cross-site-scripting-spoofing) (critical, CVSS 9.6, published 14 Jul 2026) - [CVE-2026-55005: Microsoft Exchange Server heap overflow remote code execution](https://junglewise.ai/threats/cve-2026-55005-microsoft-exchange-server-heap-overflow-remote-code-execution) (high, CVSS 8.8, published 14 Jul 2026) - [CVE-2025-53786: Microsoft Exchange Server improper authentication in hybrid deployments](https://junglewise.ai/threats/cve-2025-53786-microsoft-exchange-server-improper-authentication-in-hybrid) (high, CVSS 8, published 6 Aug 2025) - [CVE-2026-62911: Microsoft Exchange Server privilege escalation via NTLM relay to MRSProxy](https://junglewise.ai/threats/cve-2026-62911-microsoft-exchange-server-privilege-escalation-via-ntlm-relay-to) (high, CVSS 8, published 11 Aug 2026) - [CVE-2026-87692: Microsoft Exchange Server deserialization privilege elevation](https://junglewise.ai/threats/cve-2026-87692-deserialization-of-untrusted-data-in-microsoft-exchange-server) (high, CVSS 7.8, published 13 Oct 2026) - [CVE-2026-87695: Microsoft Exchange Server privilege escalation via untrusted control sphere](https://junglewise.ai/threats/cve-2026-87695-inclusion-of-functionality-from-untrusted-control-sphere-in) (high, CVSS 7.8, published 13 Oct 2026) - [CVE-2026-55009: Microsoft Exchange Server deserialization privilege escalation](https://junglewise.ai/threats/cve-2026-55009-microsoft-exchange-server-deserialization-privilege-escalation) (high, CVSS 7.8, published 14 Jul 2026) - [CVE-2026-87696: Microsoft Exchange Server cryptographic signature verification privilege escalation](https://junglewise.ai/threats/cve-2026-87696-improper-verification-of-cryptographic-signature-in-microsoft) (high, CVSS 7.5, published 13 Oct 2026) - [CVE-2026-21527: Microsoft Exchange Server UI misrepresentation spoofing vulnerability](https://junglewise.ai/threats/cve-2026-21527-microsoft-exchange-server-ui-misrepresentation-spoofing) (medium, CVSS 6.5, published 10 Feb 2026) ## Vulnerabilities per week 3 vulnerabilities in the last four weeks, up from none in the four before. | Week of | Vulns | Critical | Exploited | | --- | --- | --- | --- | | 17 Aug 2026 | 0 | 0 | 0 | | 24 Aug 2026 | 0 | 0 | 0 | | 31 Aug 2026 | 0 | 0 | 0 | | 7 Sep 2026 | 0 | 0 | 0 | | 14 Sep 2026 | 0 | 0 | 0 | | 21 Sep 2026 | 0 | 0 | 0 | | 28 Sep 2026 | 0 | 0 | 0 | | 5 Oct 2026 | 0 | 0 | 0 | | 12 Oct 2026 | 3 | 0 | 0 | | 19 Oct 2026 | 0 | 0 | 0 | | 26 Oct 2026 | 0 | 0 | 0 | | 2 Nov 2026 | 0 | 0 | 0 | | 9 Nov 2026 | 0 | 0 | 0 | ## Other Microsoft technologies - [Microsoft Windows](https://junglewise.ai/threats/technologies/windows): 2,362 vulnerabilities - [Microsoft Windows 10](https://junglewise.ai/threats/technologies/windows-10): 589 vulnerabilities - [Microsoft Windows 11 24h2](https://junglewise.ai/threats/technologies/windows-11-24h2): 565 vulnerabilities - [Microsoft Windows 11 25h2](https://junglewise.ai/threats/technologies/windows-11-25h2): 534 vulnerabilities - [Microsoft Windows Server 2025](https://junglewise.ai/threats/technologies/windows-server-2025): 534 vulnerabilities - [Microsoft Windows Server 2022](https://junglewise.ai/threats/technologies/windows-server-2022): 528 vulnerabilities - [Microsoft Windows Server 2019](https://junglewise.ai/threats/technologies/windows-server-2019): 521 vulnerabilities - [Microsoft Windows Server 2012](https://junglewise.ai/threats/technologies/windows-server-2012): 517 vulnerabilities - [Microsoft Windows 11](https://junglewise.ai/threats/technologies/windows-11): 494 vulnerabilities - [Microsoft Windows Server 2016](https://junglewise.ai/threats/technologies/windows-server-2016): 476 vulnerabilities - [Microsoft Windows 10 1809](https://junglewise.ai/threats/technologies/windows-10-1809): 380 vulnerabilities - [Microsoft Windows 10 21h2](https://junglewise.ai/threats/technologies/windows-10-21h2): 373 vulnerabilities ## Sources NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "Microsoft Exchange Server Subscription Edition vulnerabilities", https://junglewise.ai/threats/technologies/exchange-server-subscription-edition, 13 November 2026.