CISA confirms 2025 Windows Task Host flaw exploited by ransomware groups

The Cybersecurity and Infrastructure Security Agency (CISA) on August 14 confirmed that a privilege escalation flaw in the Windows Task Host was being abused by ransomware groups.

CISA’s notice follows a familiar pattern in which a flaw gets discovered and patched by a vendor, followed by a report that it was actively exploited, and then confirmation that it’s being exploited by ransomware groups.

In this case, Microsoft released a patch November 11, 2025, CISA added the flaw to its Known Exploited Vulnerabilities catalog April 13 and CISA then updated the KEV entry for CVE-2025-60710 this past Friday.

Jacob Krell, senior director of secure AI solutions and cybersecurity at Suzu Labs, said Task Host is a Windows component used to host background tasks, including scheduled maintenance and cleanup operations that can run without user interaction. The vulnerable Windows AI Recall scheduled task executes through Task Host in the NT AUTHORITY\SYSTEM, the highest privilege level on a Windows machine.

Krell explained that CVE-2025-60710 is a link-following weakness, meaning the task operates on a user-writable AppData path and performs deletion without properly checking for junctions or symbolic links.

“An attacker can abuse that behavior to make the system-level task delete attacker-selected protected files,” said Krell. “Public exploitation techniques turn that primitive into code execution as SYSTEM, converting a standard user foothold into full control of the endpoint.”

The pitfall here: system access turns an existing low-privilege foothold on one endpoint into complete control of that machine, which can dramatically accelerate a ransomware intrusion. From there, Krell said an attacker can potentially extract cached credentials, tamper with endpoint protection, establish persistence, and use that endpoint as a launch point for lateral movement.

“The typical endgame is full ransomware deployment across the environment, encrypted file shares, locked-out users, operational shutdown,” said Krell. “For organizations with large Windows 11 and Server 2025 deployments, that can translate into a broad exposure footprint.”

Bradley Smith, senior vice president and deputy CISO at BeyondTrust, added that Task Host is one of the most trusted pieces of Windows: it’s the background process that runs scheduled task code, and much of what it does runs as SYSTEM, the highest local authority the operating system has.

Smith said this flaw lets an attacker with nothing more than a basic user account redirect file operations. Task Host performs as SYSTEM, and at the end of that chain is the attacker operating as SYSTEM themselves.

“From there they can shut off the security tooling that would catch the intrusion and pull the credentials that open the door to the next machine,” said Smith. “I think the ransomware flag CISA added on Friday matters more than the severity score [of 7.8], because escalation of privilege is required for a ransomware operation.”

Roman Y. Sannikov, global research coordinator at iCounter, said we’re seeing a familiar pattern: a patch ships, and within months ransomware crews have reverse-engineered it and folded it into their operational playbook.

Sannikov said these groups run like businesses, and a reliable SYSTEM-level privilege escalation on Windows 11 and Server 2025 is high-value because it works across an enormous number of targets, usually as the second or third step in a chain once an attacker already has a foothold and needs to convert limited access into full control.

“What makes Task Host specifically dangerous is what it's trusted to run on schedule: system updates and maintenance, disk cleanup and optimization, backup operations, Windows updates, antimalware scans, report generation, and a wide range of other Windows services, many of them third-party,” said Sannikov. “Compromise that component and you're not just escalating privileges, you're sitting on the scheduler that controls an organization's backups.”

Sannikov said security teams should take CISA’s latest advisory as a signal to jump the queue, not something that waits for the next monthly patch cycle.

“Organizations that get hurt by flaws like this usually had the patch available and just hadn't gotten to it, because their prioritization ran on severity score instead of what's actively being used against real victims,” said Sannikov.