CVE-2025-55177: Meta Platforms WhatsApp Incorrect Authorization Vulnerability

Medium severity, CVSS 5.4. Actively exploited: in CISA KEV since 2025-09-02. EPSS: 4.7% chance of exploitation in the next 30 days.

Incomplete authorization of linked device synchronization messages in WhatsApp for iOS prior to v2.25.21.73, WhatsApp Business for iOS v2.25.21.78, and WhatsApp for Mac v2.25.21.78 could have allowed an unrelated user to trigger processing of content from an arbitrary URL on a target’s device. We assess that this vulnerability, in combination with an OS-level vulnerability on Apple platforms (CVE-2025-43300), may have been exploited in a sophisticated attack against specific targeted users.

Affected products

• WhatsApp WhatsApp: from 2.22.25.2, before 2.25.21.73 (fixed in 2.25.21.73); from 2.22.25.2, before 2.25.21.78 (fixed in 2.25.21.78)
• WhatsApp WhatsApp Business: from 2.22.25.2, before 2.25.21.78 (fixed in 2.25.21.78)

Published 2025-08-29. Last modified 2026-10-08.