CVE-2026-56331

MEDIUM

Capgo - Improper Error Handling in Accept Invitation Endpoint via Invalid Magic String

Title source: cna
STIX 2.1

Description

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.

References (2)

Core 2
Core References
Vendor Advisory vendor-advisory
GitHub Security Advisory (GHSA-34p8-fh3m-376x)
https://github.com/Cap-go/capgo/security/advisories/GHSA-34p8-fh3m-376x
Third Party Advisory third-party-advisory
VulnCheck Advisory: Capgo - Improper Error Handling in Accept Invitation Endpoint via Invalid Magic String
https://www.vulncheck.com/advisories/capgo-improper-error-handling-in-accept-invitation-endpoint-via-invalid-magic-string

Scores

CVSS v3 5.3
EPSS 0.0025
EPSS Percentile 16.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-209
Status published
Products (2)
Capgo/Capgo < 12.128.2
Capgo/Capgo 12.128.2
Published Jun 30, 2026
Tracked Since Jul 01, 2026