CVE-2026-45583: Microsoft Exchange Server Remote Code Execution Vulnerability

highCVSS 7.5CVE-2026-45583

Improper control of generation of code ('code injection') in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.

CSIRTS triage

vendor: Microsoft product: Exchange Server Remote code execution

What: Improper control of generation of code in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
Who is affected: Users of Microsoft Exchange Server.
Urgency: Remediation is urgent due to the high severity and potential for remote code execution.
Action: Install the latest security updates for Microsoft Exchange Server.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: high — CVSS 7.5
Published: 2026-06-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45583

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-455830.47% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45583	coverage & exploitation status	NVD · CVE.org

Recent advisories for Microsoft Exchange Server

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

criticalCVE-2026-65801: Server-side request forgery (ssrf) in Microsoft Exchange Online allows an unauthorized attacke…nvd · 2026-08-20
high[NEW] [high] Microsoft Exchange Server: Multiple vulnerabilitiescert-bund · 2026-08-12
unknownNCSC-2026-0289 [1.00] [M/H] Vulnerabilities fixed in Microsoft Exchange Serverncsc-nl · 2026-08-12
mediumCVE-2026-65813: Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker …nvd · 2026-08-11
mediumCVE-2026-62915: Missing authorization in Microsoft Exchange Server allows an authorized attacker to bypass a s…nvd · 2026-08-11
highCVE-2026-62914: Improper neutralization of input during web page generation ('cross-site scripting') in Micros…nvd · 2026-08-11