CVE-2024-39891

Twilio Authy Information Disclosure Vulnerability

Medium 5.3
Exploited: added to CISA KEV 23 Jul 2024

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.)

Key facts

Published: 2 Jul 2024
Last changed: 21 Oct 2025
Assigned by: mitre
KEV added: 23 Jul 2024
KEV fix due: 13 Aug 2024
EPSS: 1.669% likely to be exploited in the next 30 days, higher than 77.167% of CVEs (scores for 15 Nov 2026)
SSVC (CISA): Exploitation: active; Automatable: yes; Technical impact: partial

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

5.3CVSS 3.1, Mediumfrom the CNA (mitre)CVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N

What to do

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

Vendor	Product	Versions
n/a	n/a	n/a (affected)