CVE-2026-45501: 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.
CSIRTS triage
- What
- Improper neutralization of input during web page generation allows an unauthorized attacker to perform spoofing over a network.
- Who is affected
- Deployments of Microsoft Exchange Server.
- Urgency
- Remediation is important due to the medium severity and potential for spoofing attacks.
- Action
- Apply the latest security patch for Microsoft Exchange Server.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45501
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-2026-455010.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-45501 | 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.
- highCVE-2026-45583: Microsoft Exchange Server Remote Code Execution Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-45503: Microsoft Exchange Server Information Disclosure Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-45504: Microsoft Exchange Server Elevation of Privilege Vulnerabilitymsrc · 2026-06-09
- mediumCVE-2026-45500: Microsoft Exchange Server Spoofing Vulnerabilitymsrc · 2026-06-09
- mediumCVE-2026-45502: Microsoft Exchange Server Information Disclosure Vulnerabilitymsrc · 2026-06-09
- highCVE-2026-47631: Microsoft Exchange Server Spoofing Vulnerabilitymsrc · 2026-06-09
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