CVE-2024-39891

MEDIUM CISA KEV

CVSS v3

5.3

MEDIUM

EPSS Score

exploit probability

CISA KEV

Yes

known exploited

Exploitation

SSVC status

Description

In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an unauthenticated endpoint provided access to certain phone-number data, as exploited in the wild in June 2024. Specifically, the endpoint accepted a stream of requests containing phone numbers, and responded with information about whether each phone number was registered with Authy. (Authy accounts were not compromised, however.)

CISA Known Exploited Vulnerability

Date Added
7/23/2024
Patch Due Date
8/13/2024
Required Action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Technical Details

CVSS v3 Vector
3.1
Published
7/2/2024
Last Modified
11/5/2025

Frequently Asked Questions

What is CVE-2024-39891?

In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an unauthenticated endpoint provided access to certain phone-number data, as exploited in the wild in June 2024. Specifically, the endpoint accepted a stream of requests containing phone numbers, and responded with information about whether each phone number was registered with Authy. (Authy accounts were not compromised, however.)

Is CVE-2024-39891 actively exploited?

Yes. CVE-2024-39891 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 8/13/2024.

What is the CVSS score for CVE-2024-39891?

CVE-2024-39891 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string 3.1.

Is CVE-2024-39891 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.

CVE-2024-39891 Vulnerability — CVSS 5.3, MEDIUM Severity | isMalicious