Capgo before 12.128.2 contains a denial of service vulnerability in the /auth/v1/otp endpoint that prevents email verification for two-factor authentication due to captcha validation failures. Authenticated users cannot complete 2FA enrollment as the backend consistently returns HTTP 500 errors with captcha verification process failed messages, blocking access to security controls.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation poc

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Capgo Capgo unaffected
Version Status Constraints
0 affected < 12.128.2
12.128.2 unaffected —

No data.

No data.

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Vendors Products
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Project Subscriptions

Vendors Products
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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/Cap-go/capgo/security/advisories/GHSA-m53g-7gcj-x6f7 cve-icon cve-icon
https://www.vulncheck.com/advisories/capgo-denial-of-service-in-2fa-email-verification-via-auth-v1-otp-endpoint cve-icon
History

Wed, 24 Jun 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Cap-go
Cap-go cap-go
Vendors & Products Cap-go
Cap-go cap-go

Wed, 24 Jun 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Wed, 24 Jun 2026 12:00:00 +0000

Type Values Removed Values Added
Description Capgo before 12.128.2 contains a denial of service vulnerability in the /auth/v1/otp endpoint that prevents email verification for two-factor authentication due to captcha validation failures. Authenticated users cannot complete 2FA enrollment as the backend consistently returns HTTP 500 errors with captcha verification process failed messages, blocking access to security controls.
Title Capgo - Denial of Service in 2FA Email Verification via /auth/v1/otp Endpoint
Weaknesses CWE-703
References
Metrics cvssV3_1

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

cvssV4_0

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

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-06-24T14:59:10.684Z

Reserved: 2026-06-20T13:13:56.012Z

Link: CVE-2026-56338

cve-icon Vulnrichment

Updated: 2026-06-24T14:59:05.265Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-24T15:45:06Z

Weaknesses