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CVE-2026-21513 is a security feature bypass vulnerability in the Microsoft MSHTML framework. Available reporting places the flaw in the _AttemptShellExecuteForHlinkNavigate function within ieframe.dll, where URL handling and validation are insufficiently strict. The issue can be triggered through crafted content such as a malicious HTML file or a weaponized Windows shortcut that causes MSHTML and related shell/browser components to process attacker-controlled navigation data. The vulnerability bypasses protections intended to restrict execution of files originating from untrusted network sources and to enforce file-execution prompts or trust checks. Multiple reports indicate the flaw was exploited in the wild as a zero-day and could be chained with other Windows vulnerabilities to achieve code execution.
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No public exploit code observed for this vulnerability.
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Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
176 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A zero-day vulnerability in the Microsoft MSHTML framework's handling of hyperlinks in ieframe.dll that can be triggered via a crafted .lnk file embedding HTML content.
An MSHTML security bypass vulnerability identified as one of the CVEs being tested by the malware delivery infrastructure.
A specific vulnerability referenced only as smaller test material in the exposed lab; no technical details are provided in the content.
An MSHTML bypass vulnerability mentioned as a secondary file-handling flaw for which the operator kept smaller test sets.
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.