CWE-209Weakness · CWE-209

CVE-2026-56331

MEDIUM · 5.3 CVSS v3.1 Published 2026-06-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click 8 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Capgo before 12.128.2 contains improper error handling in the /private/accept_invitation endpoint that returns HTTP 500 instead of safe 4xx errors when magic_invite_string is invalid. Attackers can trigger this vulnerability using only the public key by submitting malformed magic_invite_string values to cause server errors and leak internal processing details.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Capgo before version 12.128.2 has improper error handling in the /private/accept_invitation endpoint. When a malformed magic_invite_string is submitted, the server returns an HTTP 500 error instead of a safe 4xx error. This leaks internal processing details to attackers who only need the public key to exploit the vulnerability.

MitigationImplement proper error handling to return appropriate 4xx status codes (such as 400 Bad Request or 401 Unauthorized) when the magic_invite_string is invalid, and ensure internal processing details are not exposed in error responses.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Capgo version
    Locate the package.json, package-lock.json, or running service to determine the currently deployed version of Capgo. Use commands like 'npm list capgo', check your dependency lock file, or query the service's version endpoint if available.
    Affected if The installed version is earlier than 12.128.2
  2. Verify the /private/accept_invitation endpoint response
    Send a POST request to the /private/accept_invitation endpoint with a malformed magic_invite_string (e.g., empty string, invalid format, or garbled data). Inspect the HTTP status code returned in the response.
    Affected if The endpoint returns HTTP 500 Internal Server Error instead of a 4xx status code (400, 401, or similar)
  3. Inspect error response contents
    Examine the response body from the malformed request to the /private/accept_invitation endpoint. Look for stack traces, database queries, internal paths, configuration values, or other processing details that should not be exposed.
    Affected if The error response contains internal processing details such as stack traces, SQL queries, file paths, or sensitive configuration information

You are affected if you are running Capgo before version 12.128.2 and the /private/accept_invitation endpoint returns HTTP 500 or exposes internal details when given a malformed magic_invite_string.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement proper error handling to return appropriate 4xx status codes (such as 400 Bad Request or 401 Unauthorized) when the magic_invite_string is invalid, and ensure internal processing details are not exposed in error responses.

Recommended fix Moderate confidence

Capgo version 12.128.2 or later

  1. 1. Identify the current installed version of Capgo in your environment
  2. 2. Upgrade Capgo to version 12.128.2 or later
  3. 3. Verify the upgrade was successful by checking the version number
  4. 4. Test the /private/accept_invitation endpoint with invalid magic_invite_string to confirm it now returns proper 4xx error instead of 500

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-56331 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data