ZeroHour

CVE-2026-53414

CVSS 3.1
6.5 medium
EPSS
<1%p32
Published
()
Modified
Description

Missing bounds check in the annotator function of Zoom Clients allows buffer over-read, which may allow a meeting participant to conduct a denial of service on another participant via network access.

Weakness
CWE-126
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

In the news

Zoom Annotation Flaws Could Let a Meeting Participant Hijack Another Attendee's Client

A Security researchers disclosed three Zoom annotation flaws enabling zero-click client hijacking; Zoom shipped fixes in June and July with no exploitation reported.

Researchers at A Security found three flaws in Zoom's annotation feature: CVE-2026-53413 (CVSS 8.3, buffer over-write), CVE-2026-53414 (CVSS 6.5, buffer over-read), and CVE-2026-53415 (CVSS 8.3, use-after-free). A crafted drawing object sent over the wrong message channel can overwrite adjacent memory and hijack another attendee's client with no user interaction. Fixes shipped in Zoom Workplace 7.1.5/7.0.6, VDI Client 7.0.11/6.6.16, and Zoom Rooms/Meeting SDK 7.1.0+ during June and July. No exploitation has been reported and the flaws are absent from CISA's Known Exploited Vulnerabilities catalog.

Zoom Patches “Zoomsday” Zero-Click Flaw Enabling Remote Code Execution

Zoom patched CVE-2026-53413, a zero-click annotation flaw dubbed "Zoomsday" allowing remote code execution on meeting participants' devices across all platforms.

Zoom patched four vulnerabilities, including CVE-2026-53413, a stack buffer overflow in CAnnoFormatBlock::Deserialize in the annotation protocol that allows zero-click remote code execution on another participant's device. A Security also found CVE-2026-53414, a buffer overread enabling denial-of-service crashes, and CVE-2026-53415, a use-after-free Zoom had already discovered internally. Updates shipped for Workplace 7.1.5 and 7.0.6, Rooms 7.1.5, and Meeting SDK 7.1.5 across all supported platforms.