Vulnerability · CVE-2024-39891
Twilio Authy Information Disclosure Vulnerability
Published Jul 2, 2024 · catalog updated Jun 17, 2026 · Twilio Authy
Patch now
CVE-2024-39891 is in the CISA known-exploited catalog, due Aug 13, 2024. Confirm Twilio Authy against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- Severity
- Medium5.3
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 1.67%
- Remediation
- Remediation guidance
- Affected products
- cpe twilio/authy · cpe twilio/authy authenticator · vendor Twilio Authy
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.)
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe twilio/authyversion unspecified
- cpe twilio/authy authenticatorversion unspecified
- vendor Twilio Authyversion unspecified
How to fix CVE-2024-39891
Recommended remediation
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. CISA due date Aug 13, 2024.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2024-39891 is in the CISA known-exploited catalog, due Aug 13, 2024. Confirm Twilio Authy against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Affected version ranges are not on this record. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
What should an analyst verify?
CWE-203: Observable Discrepancy. EPSS 1.67%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jul 2, 2024 · Catalog
Detected
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
Jul 23, 2024 · CISA KEV
Known exploited
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Aug 13, 2024 · CISA KEV
Remediation due
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Jun 17, 2026 · Catalog
Updated
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
Sources
- CISA KEVConfirmed exploitationCVE-2024-39891
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.
cisa.gov - CVE.orgVulnerability recordCVE-2024-39891
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2024-39891
30-day exploitation probability 1.7%
first.org - NIST NVDVulnerability recordCVE-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
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2024-39891
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.
vulncheck.com
References
Freshness
Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.