Microsoft Copilot reveals secret input that allowed it to be hacked

18 August 2026 at 13:00

It’s not every day that attackers can force a frontier AI model to cough up user passwords and other sensitive data without user confirmation. That’s exactly what researchers recently did to Microsoft 365 Copilot for enterprise. Even more unusual is the source they tapped to discover the critical vulnerability that made their exploit possible. Rather than employing reverse engineering or other traditional vulnerability-hunting methods, they asked Copilot. The LLM assistant readily complied.

Researchers at security firm Varonis knew they wanted to create an exploit that would exfiltrate user data when a user did nothing more than click on a link. Like most AI assistants today, Copilot steadfastly refused and made clear that sensitive prompts like that require explicit user consent in the form of a gesture, such as pressing a return key or other key. In response, the researchers peppered Copilot with questions about the guardrails that required user confirmation before the assistant could execute powerful commands.

Loose lips sink ships

The dialog was like a game of 20 questions. Each answer provided a new clue that divulged information about the complex safety mechanism. Why was auto-execution impossible, they asked. What URL structures and deep links were involved? What happens when a page is loaded with input already in the prompt field? Each answer provided a deeper view into the guardrail and its limits. Eventually, Copilot provided a stunning Microsoft trade secret—an undocumented prompt parameter that completely bypassed the requirement for user consent.

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Vulnerability giving attackers full control of Macs is under active exploitation

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By: Dan Goodin

14 August 2026 at 18:32

Dutch officials have warned that a high-severity macOS vulnerability that allows attackers to execute malicious code is under active exploitation.

“The NCSC has received a notification indicating that active abuse of this vulnerability has been observed on multiple systems on which port 5900 was accessible from the Internet,” the Netherlands National Cyber Security Centrum warned earlier this week. “In all these cases, root had been accessed on the affected system and a Monero crypto miner had been placed.”

Do you know if your screen sharing is on?

The vulnerability, tracked as CVE-2026-65400, received a patch from Apple last week for macOS Tahoe, Sequoia, and Sonoma. The vulnerability, with a severity rating of 7.1 out of 10, stems from a bug in the macOS screen sharing capability, which allows a remote party to view the screen and control the keyboard and mouse while a machine is turned on. A flaw in the “state management,” which keeps track of preceding events, user interactions, variables, and other system states, is the underlying cause.

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Thousands of servers can be backdoored by exploiting buggy motherboard controllers

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By: Dan Goodin

5 August 2026 at 22:35

Thousands of Internet-connected servers sold by the world’s biggest manufacturers can be remotely backdoored by exploiting critical vulnerabilities—some more than a decade old—that lurk deep inside system motherboards, according to research presented Wednesday.

Baseboard management controllers are miniature computers that are embedded into the motherboards of virtually every enterprise server. The microcontrollers, typically abbreviated as BMCs, run with their own operating system firmware, network stack, and IP address. Administrators rely on them to monitor the physical status of large fleets of servers and to perform a variety of tasks, including rebooting machines, installing updates, and even reinstalling operating systems. BMCs provide what’s known as “lights out” and “out-of-band” management because they work even when servers they’re attached to are turned off or are unresponsive.

A “pervasive, under-monitored, under-patched parallel attack surface”

Researchers have warned since at least 2013 that BMCs present a golden opportunity for hackers looking for ways to gain deep and persistent access to datacenters. The chief culprit was IPMI, the protocol that allows BMCs to operate independently of servers and to perform administrative tasks. Vulnerabilities in this firmware made it possible for attackers to remotely execute malicious code on the controllers and, from there, infect the servers they manage.

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Max-severity Exchange server flaw under active exploitation by Kremlin hackers

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By: Dan Goodin

30 July 2026 at 20:57

Russian state hackers are using a maximum-severity vulnerability in Microsoft Outlook’s Exchange Server to backdoor unpatched machines and steal credentials and other confidential information from them, security researchers said Thursday.

The attacks are coming from TA488, a tracking name for a group working on behalf of the Kremlin, Proofpoint researchers said Thursday. Proofpoint and the National Security Agency jointly warned last week that the group, also tracked as Laundry Bear and Void Blizzard, had been carrying out similar attacks by exploiting a zero-day vulnerability in an email service from Zimbra. The revelation that TA488 is also exploiting the Exchange Server vulnerability to install advanced malware when a user does nothing other than open an email sent to an Outlook Web Access (OWA) account has elevated the group’s profile and assessments of its abilities.

Doubling down

“TA488 is doubling down on the use of ‘half-click’ exploits—where opening the email is enough to trigger compromise—with significantly improved loading mechanisms, techniques, and malware, signaling an improvement in the group’s tradecraft and capability,” Proofpoint researchers wrote. “This novel infection chain ends with a previously unknown JavaScript browser-based implant we call OWAReaper, purpose-built for persistent access inside OWA.”

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Reading view

Loose lips sink ships

Do you know if your screen sharing is on?

A “pervasive, under-monitored, under-patched parallel attack surface”

Doubling down