# CVE-2026-56312: Capgo improper authentication in accept_invitation endpoint

Source: https://junglewise.ai/threats/cve-2026-56312-capgo-improper-authentication-in-accept-invitation-endpoint  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-10. Updated: 2026-07-10  
License: CC BY 4.0 with a link back

CVE-2026-56312 · Severity: medium · CVSS 6.5 · Published 2026-07-10

Capgo, a platform for managing app updates, contains a flaw in how it handles new user invitations. An attacker can bypass security CAPTCHA checks to automatically create unauthorized accounts and exhaust valid invitation links. This could lead to service disruption, the creation of unwanted 'stuck' accounts, and the exhaustion of legitimate user invites.

Technologies: [Capgo](https://junglewise.ai/threats/technologies/capgo). Vendors: [Capgo](https://junglewise.ai/threats/vendors/capgo).

## Quick answers

**Is CVE-2026-56312 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-56312 being exploited in the wild.

**How severe is CVE-2026-56312?** Medium severity, with a CVSS score of 6.5, published 10 July 2026.

**Which products and versions are affected?** Capgo before 12.128.2.

**Is there a fix for CVE-2026-56312?** A patch was published on 2026-07-10: Version 12.128.2 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-56312 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-56312?** Check whether you run Capgo at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An improper authentication vulnerability exists in the `accept_invitation` endpoint of Capgo. The root cause is located in `supabase/functions/_backend/private/accept_invitation.ts`, where the server invokes `supabaseAdmin.auth.admin.createUser()` before CAPTCHA enforcement is completed. CAPTCHA validation is only applied during a subsequent `signInWithPassword` call; if that call fails, the user account has already been persisted in the database. A remote, unauthenticated attacker can exploit this by sending POST requests with a valid invitation string but an invalid CAPTCHA token, leading to account creation and the 'burning' of invitation links. The issue is resolved in version 12.128.2.

## Affected products

- Capgo Capgo before 12.128.2

## Timeline

- 2026-02-10: advisory: GitHub Security Advisory published
- 2026-07-10: disclosed: NVD publication date
- 2026-07-10: patched: Version 12.128.2 released

## References

- [https://github.com/Cap-go/capgo/security/advisories/GHSA-whc5-fvr7-g5v3](https://github.com/Cap-go/capgo/security/advisories/GHSA-whc5-fvr7-g5v3)
- [https://www.vulncheck.com/advisories/capgo-account-creation-before-captcha-validation-in-accept-invitation-endpoint](https://www.vulncheck.com/advisories/capgo-account-creation-before-captcha-validation-in-accept-invitation-endpoint)

## Related threats

- [Capgo access control bypass in SSO provider configuration](https://junglewise.ai/threats/cve-2026-100612-capgo-capgo-app-through-version-12-261-0-contains-an-incomplete)
- [Capgo information disclosure in SSO check-domain endpoint](https://junglewise.ai/threats/cve-2026-56336-capgo-information-disclosure-in-sso-check-domain-endpoint)
- [Capgo improper authorization in SSO prelink endpoint](https://junglewise.ai/threats/cve-2026-56313-capgo-improper-authorization-in-sso-prelink-endpoint)
- [Capgo insufficient authentication in email change endpoint](https://junglewise.ai/threats/cve-2026-56308-capgo-insufficient-authentication-in-email-change-endpoint)
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