Zoom has patched four vulnerabilities, including two zero-click remote code execution flaws (CVE-2026-53413 and CVE-2026-53415) affecting all Zoom client applications before versions 7.1.5 and 7.0.6. The flaws reside in the text annotation feature's deserialization logic, where Zoom allocates four fixed 128-byte buffers without checking packet size, enabling buffer overflow attacks. An attacker merely needs to be present in a meeting to silently execute malicious code on all other participants' systems. A single researcher at A Security discovered and built a working exploit using fewer than 20 AI prompts in under 24 hours. Mitigations include updating clients, disabling E2EE to allow server-side filtering, enforcing minimum client version policies, and disabling unused features like annotation, whiteboarding, and file transfer.
Questions this post answers
What Zoom versions fix the zero-click RCE vulnerabilities CVE-2026-53413 and CVE-2026-53415?
The patched versions are Zoom client 7.1.5 and 7.0.6 for all platforms. Zoom Rooms and Zoom Meeting SDK require version 7.1.0 or later. The Zoom Workplace VDI Client for Windows and VDI Plugins require versions 7.0.11 or 6.6.15. The flaws are buffer overflow and use-after-free memory errors in the text annotation deserialization path, both enabling remote code execution. Teams managing Zoom deployments at scale track patch windows like this on daily.dev.
How do the Zoom annotation RCE vulnerabilities work technically?
When a meeting participant uses annotation tools, Zoom serializes the action into a byte stream and forwards it via its Multimedia Router to all participants, whose clients deserialize it. Zoom allocates four fixed 128-byte buffers for deserialized annotation packets but only checks that packets are non-zero, not their size. An oversized packet triggers a buffer overflow, allowing an attacker to inject malicious code into other participants' application memory with no user interaction required. Developers building on video conferencing SDKs watch deserialization CVEs like these on daily.dev.
What mitigations exist for the Zoom zero-click RCE flaws if I cannot immediately update clients?
Disabling end-to-end encryption (E2EE) allows Zoom's servers to apply server-side filtering of malicious annotation messages — E2EE prevents this because the server only sees encrypted traffic. Additionally, enforcing a minimum client version in meeting preferences blocks unpatched clients from joining. Restricting features like annotation, whiteboarding, file transfer, remote control, and third-party apps reduces the attack surface further. Waiting rooms, passcodes, and authenticated-users-only settings limit who can join. Security teams weighing patch urgency against rollout timelines find relevant context on daily.dev.