CVE-2026-56338 json
Capgo - Denial of Service in 2FA Email Verification via /auth/v1/otp Endpoint
published 4mo ago modified 4mo ago also EUVD-2026-38752
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 42%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Capgo Capgo 12.128.2
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Check with FencerCISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4mo ago
Exploit prediction
0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/Cap-go/capgo/security/advisories/GHSA-m53g-7gcj-x6f7 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | 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 |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| CNA | 4.0 | 6.9 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- Capgo Capgo
Classification
- Weakness
-
- CWE-703 Improper Check or Handling of Exceptional Conditions
References
-
github.com
/Cap-go/capgo/security/advisories/GHSA-m53g-7gcj-x6f7
vendor-advisory, exploit
-
vulncheck.com
/advisories/capgo-denial-of-service-in-2fa-email-verification-via-auth-v1-otp-endpoint
third-party-advisory
Sources
- CVE List CVE-2026-56338
- NVD CVE-2026-56338
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