Twilio Authy Information Disclosure Vulnerability
n/a — n/a
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.)
5.3
1.5%
Vector breakdown
- Attack complexity
- Low
- Attack vector
- Network
- Availability
- None
- Confidentiality
- Low
- Integrity
- None
- Privileges required
- None
- Scope
- Unchanged
- User interaction
- None
CVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N
- Published
- Jul 2, 2024
- Modified
- Oct 21, 2025
- Added to KEV
- Jul 23, 2024
- Federal patch due
- Aug 13, 2024
CISA required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Weakness classification
Proof-of-concept & exploitation references
Weaponization
Public repositories whose name or description references CVE-2024-39891, found via a live GitHub search at request time. These are community-sourced signals, not a verified working exploit - cross-check each one before relying on it, and treat higher star counts and recent activity as (weak) corroboration, not proof.
No public GitHub repositories referencing CVE-2024-39891 were found at last check. Absence here is not proof no exploit exists - see the references below for vendor advisories and write-ups.
References
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.)
How severe is CVE-2024-39891?
CVE-2024-39891 has a CVSS base score of 5.3 out of 10 (CVSS 3.1).
Is CVE-2024-39891 actively exploited in the wild?
Yes. CVE-2024-39891 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added Jul 23, 2024, meaning CISA has confirmed evidence of active exploitation.
What is the EPSS score for CVE-2024-39891?
1.5% - meaning FIRST.org's EPSS model estimates a 1.5% probability this vulnerability will be exploited in the wild within 30 days (71% percentile among all scored CVEs).
What type of vulnerability is CVE-2024-39891?
CVE-2024-39891 is classified under CWE-203 (CWE-203 Observable Discrepancy).
Cross-checked against
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