CISA orders feds to patch Windows flaw exploited as zero-day

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has ordered federal agencies to secure their Windows systems against a vulnerability exploited in zero-day attacks.

Tracked as CVE-2026-32202, this security flaw was reported by cybersecurity firm Akamai, which described it as a zero-click vulnerability left behind after Microsoft incompletely patched a remote code execution flaw (CVE-2026-21510) in February.

As CERT-UA revealed, the Russian APT28 (aka UAC-0001 and Fancy Bear) cyberespionage group exploited CVE-2026-21510 in attacks against Ukraine and EU countries in December 2025 as part of an exploit chain that also targeted a LNK file flaw (CVE-2026-21513).

"Microsoft fixed the initial RCE (CVE-2026-21510), an authentication coercion flaw (CVE-2026-32202) remained. This gap between path resolution and trust verification left a zero-click credential theft vector via auto-parsed LNK files," Akamai said in a Thursday report.

As Microsoft explains, remote attackers who successfully exploit the vulnerability in low-complexity attacks by sending "the victim a malicious file that the victim would have to execute," could "view some sensitive information" on unpatched systems.

Microsoft flagged the CVE-2026-3220 flaw as exploited in attacks on Sunday after BleepingComputer reached out last week to ask why the advisory released during the April 2026 Patch Tuesday had an exploitability assessment of 'Exploitation Detected' while the vulnerability was flagged as not exploited.

A Microsoft spokesperson has yet to reply to a second email requesting more information about the CVE-2026-32202 attacks, including whether APT28 hackers also exploited this zero-click vulnerability.

Feds ordered to patch by May 12

On Tuesday, CISA added CVE-2026-32202 to its Known Exploited Vulnerabilities (KEV) Catalog, ordering Federal Civilian Executive Branch (FCEB) agencies to patch their Windows endpoints and servers within two weeks, by May 12, as mandated by Binding Operational Directive (BOD) 22-01.

"This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise," the cybersecurity agency warned.

"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable."

Although BOD 22-01 applies only to U.S. federal agencies, CISA has urged all security teams to prioritize deploying patches for CVE-2026-32202 and securing their organizations' networks as soon as possible.

Threat actors are also actively exploiting three recently disclosed Windows security vulnerabilities (dubbed BlueHammer, RedSun, and UnDefend) in attacks aimed at gaining SYSTEM or elevated administrator privileges, with the latter two still awaiting patches.

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