Linked CVE review

Deploy Microsoft ESU security update KB5103213

Linked CVEs: 4
Confirmed exploited: 0
PoC or lab evidence: 0
Maximum CVSS: 9.6

Evidence is kept separate

Confirmed exploitation, public exploit material, EPSS probability and CVSS severity answer different questions. “No confirmation recorded” means the checked sources do not currently confirm exploitation. It is not proof that exploitation has not occurred.

4 of 4 linked CVEs shown

Confirmed exploitedCVSS above 9.0

CVE and description	Severity	Exploit reality	Forecast and access	Remediation
CVE-2026-55009 Scheduled assessment Microsoft Exchange Server Elevation of Privilege Vulnerability Deserialization of untrusted data in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.	7.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 2.51% · 84.3th percentileForecast date: 2026-10-07LOCAL · LOW complexity · LOW privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-55005 Scheduled assessment Microsoft Exchange Server Remote Code Execution Vulnerability Heap-based buffer overflow in Microsoft Exchange Server allows an authorized attacker to execute code over a network.	8.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 1.01% · 62.0th percentileForecast date: 2026-10-07NETWORK · LOW complexity · LOW privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-55008 Critical technical severity Microsoft Exchange Server Spoofing Vulnerability Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.	9.6 · CVSS 3.1 · CriticalSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.86% · 57.3th percentileForecast date: 2026-10-07NETWORK · LOW complexity · NONE privileges · REQUIRED user interaction	Within 7 daysCritical technical severity; prioritise exposed affected systems while verifying vendor guidance.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.
CVE-2026-55006 Scheduled assessment Microsoft Exchange Server Elevation of Privilege Vulnerability Insufficient granularity of access control in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.	7.8 · CVSS 3.1 · HighSource: CNA	No confirmation recordedNo CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.None recordedNo exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.	EPSS: 0.30% · 20.6th percentileForecast date: 2026-10-07LOCAL · LOW complexity · LOW privileges · NONE user interaction	Within 7 daysHigh technical severity; prioritise exposed affected systems while verifying vendor guidance.Awaiting fix. No fixed version is explicitly recorded in the structured CVE data.