Dropbox Says 5,000 Accounts Were Compromised Through Lenovo ID Authentication Flaw

Cybersecuritynews •Guru Baran • September 2, 2026

Dropbox has disclosed that approximately 5,000 user accounts were compromised in August after attackers exploited a weakness involving its Lenovo ID sign-in integration. The incident highlights the security risks that can arise when cloud platforms trust third-party identity providers without requiring strong, account-level verification before granting access. According to notifications sent to affected users, unauthorized […]

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This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Dropbox Accounts Compromised via Lenovo ID Authentication Flaw Between August 4 and August 21, 2026, approximately 5,000 Dropbox accounts were compromised due to a flaw in Lenovo's email verification process. Attackers exploited this vulnerability to register fraudulent Lenovo IDs using victims' email addresses, allowing them to access Dropbox accounts without needing passwords. The breach affected users who did not have two-factor authentication enabled. Dropbox has since terminated all sessions authenticated through Lenovo IDs and implemented new security measures requiring users to enter their Dropbox passwords for Lenovo ID logins. Notifications were sent to affected users starting August 31, 2026. The incident is linked to known vulnerabilities CVE-2026-55075 and CVE-2026-14781, highlighting risks in federated identity systems. 9 sources 66

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Dropbox Says 5,000 Accounts Were Compromised Through Lenovo ID Authentication Flaw

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Extracted Entities

Attack Types (1)

CWE Weaknesses (1)

MITRE ATT&CK (1)

Platforms (1)

Tools (1)