CVE-2024-39891
In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an...
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.)
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
5.3
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.)
- Record
CVE-2024-39891- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N - Weakness
- CWE-203
- Updated
- 2026-11-02
EUVDEUVD-2024-38291
5.3
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.)
- Record
EUVD-2024-38291- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vg5j-h7r8-88x8
5.3
In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an...
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. (Authy accounts were not compromised, however.)
- Record
GHSA-vg5j-h7r8-88x8- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
CISA KEV No score
Twilio Authy Information Disclosure Vulnerability
Twilio Authy contains an information disclosure vulnerability in its API that allows an unauthenticated endpoint to accept a request containing a phone number and respond with information about whether the phone number was registered with Authy.
- Record
CVE-2024-39891- Weakness
- CWE-203
- Updated
- 2026-11-02
NVD
5.3
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.)
- Record
CVE-2024-39891- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-39891 is a medium vulnerability (CVSS 5.3) in Twilio Authy, published July 2, 2024. CISA lists it as known to be exploited, since July 23, 2024. EUVD reports exploitation since July 23, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.67%, the 76th percentile. No source names a fixed version.
References
cwe.mitre.org/data/definitions/203.html
twilio.com/docs/usage/security/reporting-vulnerabilities
twilio.com/en-us/changelog
bleepingcomputer.com/news/security/hackers-abused-api-to-verify-millions-of-authy-mfa-phone-numbers
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-39891
nvd.nist.gov/vuln/detail/CVE-2024-39891
github.com/advisories/GHSA-vg5j-h7r8-88x8