Elevation of Privilege in Microsoft Exchange Server
CVE-2025-64666 is an elevation of privilege vulnerability in Microsoft Exchange Server caused by improper input validation. According to the provided content, exploitation allows an authenticated low-privilege user to elevate privileges to administrator rights over the network. The issue affects Microsoft Exchange Server and was reported by the NSA. The available information does not identify the specific vulnerable function or code path.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
10 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
An escalation of privilege vulnerability in Microsoft Exchange Server due to improper input validation. Rated Important, exploitation is considered less likely, but could be critical if chained with other vulnerabilities.
An elevation of privilege vulnerability in Microsoft Exchange Server, reported by the NSA. Exploitation is considered unlikely and requires significant preparation.
An elevation of privilege vulnerability in Microsoft Exchange Server, reported by the NSA. Exploitation is considered unlikely and requires significant preparation.
A Microsoft December 2025 security update vulnerability affecting Microsoft Exchange Server.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.