CASCACascade Atlas

Evidence dossier

CVE-2024-39891

CVE-2024-39891

55.7–70.7Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

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.)

State
PUBLISHED
Published
Jul 2, 2024
Updated
Oct 21, 2025
Evidence coverage
85%
CISA KEVCatalog member

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

FIRST EPSS1.48%

2026-07-18 · v2026.06.15 · percentile 71.0%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

mitreoriginal assertion
container

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 KEVoriginal assertion
observed_exploitation

Twilio Authy Information Disclosure Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.014770000000; percentile 0.709780000000

Applicability

Cited product scope

Trace impact →
n/an/a
[{"status": "affected", "version": "n/a"}]unknown
twilioauthy_2-factor_authentication
[{"status": "affected", "version": "0", "lessThan": "26.1.0", "versionType": "custom"}, {"status": "affected", "version": "0", "lessThan": "25.1.0", "versionType": "custom"}]unknown
twilioauthy_2-factor_authentication
[{"status": "affected", "version": "0", "lessThan": "26.1.0", "versionType": "custom"}, {"status": "affected", "version": "0", "lessThan": "25.1.0", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:twilio:authy_authenticator:*:*:*:*:*:android:*:*; end excluding 25.1.0supported
Unknown vendorUnknown product
cpe:2.3:a:twilio:authy:*:*:*:*:*:iphone_os:*:*; end excluding 26.1.0supported

Assessments

CVSS by origin

5.3
nvd@nist.govCVSS 3.1 · role PrimaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3
cve@mitre.orgCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
5.3
mitreCVSS 3.1 · role unknownCVSS:3.1/AC:L/AV:N/A:N/C:L/I:N/PR:N/S:U/UI:N

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.