Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2024-39891

57
FAUCET Score

CVE-2024-39891 is an unauthenticated endpoint vulnerability in the Twilio Authy API, affecting Authy Android versions prior to 25.1.0 and Authy iOS versions prior to 26.1.0. This flaw allowed attackers to determine if a phone number was registered with Authy by sending a stream of requests, though Authy accounts themselves were not compromised. With a CVSS score of 5.3 (Medium), this vulnerability is easily exploitable over the network with low attack complexity and no user interaction required, primarily leading to information disclosure (C:L). The FAUCET Risk Score of 99/100 highlights its significant risk despite the moderate CVSS. This CVE is actively exploited in the wild, as confirmed by its inclusion in the KEV catalog. While no public exploit code (Metasploit, Nuclei, ExploitDB) is currently available, it has garnered substantial community discussion and media coverage, indicating high awareness of its exploitation.

Impacted Technologies

VendorProductVersion(s)CPE
< 26.1.0CPE matchmatch criteria
cpe:2.3:a:twilio:authy:*:*:*:*:*:iphone_os:*:*
< 25.1.0CPE matchmatch criteria
cpe:2.3:a:twilio:authy_authenticator:*:*:*:*:*:android:*:*

CVSS Data

CVSS version used by this source: 3.1

5.3MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
3.9
Impact Score
1.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.48%
Probability of exploitation in next 30 days
EPSS Percentile
71.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Added to KEV · Jul 23, 2024
This CVE's current EPSS score of 0.0148 is in the 54th percentile among its peer group of 23,723 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cisa.gov / known-exploited-vulnerabilities-catalog
US Government Resource
cwe.mitre.org / data/definitions/203.html
Technical Description
bleepingcomputer.com / news/security/hackers-abused-api-to-verify-millions-of-authy-mfa-phone-numbers
Press/Media Coverage
twilio.com / docs/usage/security/reporting-vulnerabilities
Product
twilio.com / en-us/changelog
Release Notes