FULL STORY
Copilot's CoSnitch Flaw: Disclosure to Patch
Varonis disclosed the CoSnitch flaw letting attackers make Copilot leak data; Microsoft patched it, and researchers later demoed the full attack chain.
2026-08-18 ~ 2026-08-24 · 3 episodes · 8 posts
Episode 1 · Researchers Trick Microsoft Copilot Into Revealing Its Own Exploits (2026-08-18, 3 posts)
Varonis researchers exploited the "CoSnitch" flaw (CVE-2026-24301) in Microsoft 365 Copilot by prompting it to reveal its own security controls and secret parameters, enabling theft of enterprise data and highlighting AI assistants' vulnerability to adversarial attacks.
- Microsoft Copilot Leak Reveals Hack to Bypass User Confirmation — luisdans · 2026-08-18
- Researchers Trick Copilot into Revealing How to Hack Itself — homothebrave · 2026-08-19
- Researchers trick Microsoft Copilot into exposing its own one-click data exfiltration flaw — mkheck · 2026-08-19
Episode 2 · Microsoft Patches Copilot Flaw That Let One Click Steal Data (2026-08-20, 3 posts)
Microsoft patched a critical Copilot vulnerability (CVE-2026-24301, dubbed CoSnitch) found by Varonis, which allowed attackers to silently exfiltrate victims' Gmail, Google Drive, and calendar data with a single malicious link click.
- Researchers tricked Copilot into leaking an undocumented parameter enabling one-click Gmail/Drive theft — heypearlai · 2026-08-20
- Microsoft patches critical Copilot flaw CoSnitch: one click siphons data from linked accounts — emmanuelvivier · 2026-08-20
- Critical Microsoft Copilot CoSnitch Vulnerability Exposes Data via Single Click — emmanuelvivier · 2026-08-21
Episode 3 · Researchers demo CSP-bypass attack chain stealing data from Copilot (2026-08-24, 2 posts)
Security researchers demonstrated attacks on Microsoft Copilot: a Varonis-found flaw leaked an undocumented URL in refusals, which could be chained with CSP bypass and memory poisoning to persistently exfiltrate data.
- Copilot Hack: Leaked URL Parameter Allowed Autorun Attacks — jonerp · 2026-08-24
- Copilot Exfiltration via CSP Bypass and Memory Poisoning — wunderwuzzi23 · 2026-08-24