Windows NTLM searchConnector-ms NTLM Response Disclosure / Spoofing
CVE-2026-21249 is a Microsoft Windows NTLM vulnerability in the parsing of searchConnector-ms files. The provided content indicates the flaw is caused by improper input validation / external control of a file name or path, allowing a crafted searchConnector-ms file or related malicious content to trigger NTLM authentication behavior and disclose NTLM responses in the security context of the current user. Microsoft and third-party references describe it as a spoofing issue, while supporting analysis also characterizes the practical effect as disclosure of NTLM responses. The issue is tracked as ZDI-26-083 / ZDI-CAN-28491 and affects Microsoft Windows versions listed in Microsoft’s February 2026 security updates.
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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
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Remediation
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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
7 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A spoofing vulnerability affecting Windows NTLM.
A spoofing vulnerability affecting Windows NTLM.
A spoofing vulnerability in Windows NTLM (no additional details provided in the content).
A spoofing vulnerability in Windows NTLM.
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.