Microsoft has updated its security advisory to confirm that a recently patched Windows Shell vulnerability CVE-2026-32202 has been actively exploited in the wild. The flaw, which carries a CVSS score of 4.3, was originally addressed as part of Microsoft’s April 2026 Patch Tuesday update, but the company quietly revised its advisory on April 27 after acknowledging that the original exploitability assessment had been published with incorrect information.
What Does the Vulnerability Do?
CVE-2026-32202 is a spoofing vulnerability rooted in a protection mechanism failure within Windows Shell. An attacker exploiting it over a network can access sensitive information on a victim’s machine. To trigger the flaw, the attacker must send the victim a malicious file that the victim then opens. The impact is limited to data exposure the attacker cannot modify data or affect system availability, but in the context of how it is being chained with other vulnerabilities, the consequences are significant.
The APT28 Connection
According to Akamai security researcher Maor Dahan, who discovered and reported the bug, CVE-2026-32202 stems from an incomplete patch for an earlier flaw, CVE-2026-21510. That vulnerability had already been weaponized by the Russian state-sponsored hacking group APT28 (also known as Fancy Bear, Forest Blizzard, and Pawn Storm) in a campaign targeting Ukraine and European Union nations in late 2025.
In that campaign, APT28 combined CVE-2026-21510 with a second flaw, CVE-2026-21513 a protection mechanism failure in the MSHTML Framework using a malicious Windows Shortcut (LNK) file to deliver the exploit chain. The combination effectively bypassed Microsoft Defender SmartScreen and allowed attacker-controlled code to execute on victim machines. Both vulnerabilities were patched by Microsoft in February 2026.
Why the February Patch Was Not Enough
While the February 2026 patch addressed the remote code execution component of the original attack, it left a critical gap. When a victim opens a specially crafted LNK file containing a UNC path pointing to an attacker-controlled server, Windows automatically initiates an SMB connection to that server to resolve the path without requiring any additional user interaction. This SMB handshake triggers automatic NTLM authentication, silently sending the victim’s Net-NTLMv2 credential hash to the attacker.
Those hashes can then be used in NTLM relay attacks or cracked offline to recover plaintext passwords. This zero-click credential theft vector the gap left between path resolution and trust verification — is precisely what CVE-2026-32202 represents, and it remained unaddressed even after the original exploit chain was patched.
What to Do
Organizations running Windows should ensure they have applied the full April 2026 Patch Tuesday update, which includes the fix for CVE-2026-32202. Security teams should also monitor for unusual outbound SMB traffic, enforce SMB signing across the network, and consider blocking outbound connections on ports 445 and 139 where possible to reduce exposure to NTLM relay attacks.