CVE-2026-56234

Capgo - Password Spraying via Public-Key Accessible Credential Validation Endpoint

Published Jun 23, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
Capgo before 12.128.2 contains a credential validation vulnerability in the POST /functions/v1/private/validate_password_compliance endpoint that is callable using only the public Supabase key without authentication. The endpoint is CORS-permissive with wildcard origin allowance and lacks rate limiting, enabling attackers to perform password spraying and credential stuffing attacks to compromise user accounts.

Analysis

AI-generated

Technical impact

A credential validation endpoint in Capgo can be invoked by using only the public Supabase key, with no authentication required. The endpoint is CORS‑permissive, allowing any origin to call it, and it lacks rate limiting. An attacker can repeatedly submit guessed passwords for known usernames, effectively performing password spraying or credential stuffing to compromise user accounts. The weakness belongs to CWE‑307, describing insecure authentication due to improper safeguards against credential enumeration.

Affected Systems

Capgo software, versions earlier than 12.128.2, is affected. Administrators using these releases should verify the firmware or application version and plan an upgrade.

Risk and Exploitability

The CVSS score of 6.9 indicates a moderate severity. Because the public key is normally publicly accessible and the endpoint is reachable from any origin, the likelihood of exploitation is high. No rate limiting means an attacker can submit thousands of credential attempts in a short period, increasing the probability of successful account takeover. The vulnerability is not listed in the CISA KEV catalog and no EPSS data is available, but the described attack vector strongly suggests that this flaw can be abused in the wild.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Upgrade Capgo to version 12.128.2 or later to enforce authentication and enable rate limiting on the credential validation endpoint.
  • Modify the CORS configuration to allow only trusted origins or remove the wildcard origin setting.
  • Implement or enable account lockout or rate limiting on the credential validation service to reduce the success rate of password‑spraying attempts.

Generated by OpenCVE AI on June 23, 2026 at 13:26 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Cap-go
Cap-go cap-go
Vendors & Products Cap-go
Cap-go cap-go
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Capgo before 12.128.2 contains a credential validation vulnerability in the POST /functions/v1/private/validate_password_compliance endpoint that is callable using only the public Supabase key without authentication. The endpoint is CORS-permissive with wildcard origin allowance and lacks rate limiting, enabling attackers to perform password spraying and credential stuffing attacks to compromise user accounts.
Title Capgo - Password Spraying via Public-Key Accessible Credential Validation Endpoint
Weaknesses CWE-307
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-307

    Improper Restriction of Excessive Authentication Attempts

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jun 23, 2026, 1:57 PM
Reserved
Jun 19, 2026, 9:50 PM
Status
Deferred
Published
Jun 23, 2026, 1:16 PM
Modified
Jun 23, 2026, 3:16 PM