EUVD-2026-40440
GHSA-994r-m5r3-f3p9
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/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
Network-reachable, no auth required (PR:N), low-complexity; impact limited to partial confidentiality via leaked error details, no integrity or availability consequence.
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
Lifecycle Timeline
2DescriptionCVE.org
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.
AnalysisAI
Improper error handling in Capgo's /private/accept_invitation endpoint before version 12.128.2 allows unauthenticated network attackers to trigger HTTP 500 Internal Server Error responses by submitting malformed magic_invite_string values, leaking internal processing details in violation of CWE-209. Exploitation requires no privileges or user interaction - only the publicly accessible endpoint and knowledge of its path - making any internet-exposed Capgo instance susceptible to targeted reconnaissance. No public exploit has been identified and this vulnerability is not listed in CISA KEV; the risk is constrained to information disclosure that could support a broader attack chain.
Technical ContextAI
Capgo is an open-source over-the-air (OTA) update platform for Capacitor-based mobile applications, serving as a self-hostable alternative to Ionic Appflow. The vulnerability resides in the server-side /private/accept_invitation API endpoint, which is responsible for processing invitation tokens represented by the magic_invite_string parameter. The root cause is CWE-209 (Generation of Error Message Containing Sensitive Information): when an attacker submits an invalid or malformed token, the server fails to gracefully catch and translate the error into a safe HTTP 4xx client error response, instead propagating the raw internal exception as an HTTP 500 response that may contain stack traces, internal state, framework details, or configuration hints. The CPE string cpe:2.3:a:capgo:capgo:*:*:*:*:*:*:*:* indicates the flaw affects all Capgo versions across all platforms prior to the 12.128.2 release.
RemediationAI
Upgrade to Capgo version 12.128.2 or later, which corrects the improper error handling in the /private/accept_invitation endpoint by returning appropriate HTTP 4xx client error responses for invalid magic_invite_string values rather than propagating internal exceptions as HTTP 500 responses. Full details are available in the vendor GitHub Security Advisory at https://github.com/Cap-go/capgo/security/advisories/GHSA-34p8-fh3m-376x. If immediate patching is not feasible, restrict access to the /private/accept_invitation endpoint at the network perimeter via WAF rules or reverse proxy ACLs, limiting requests to trusted source IPs or authenticated network segments - note this compensating control may disrupt legitimate invitation acceptance flows for users on untrusted networks and should be paired with an expedited upgrade timeline.
Authentication bypass in Capgo before 12.128.2 lets remote unauthenticated attackers mint arbitrary API keys by tamperin
Cross-domain SSO account takeover in Capgo before 12.128.2 allows an attacker with enterprise org admin access and a mal
Account pre-registration hijack in Capgo before 12.128.2 lets a remote unauthenticated attacker claim an account under a
Authentication bypass in Capgo prior to version 12.128.2 lets attackers defeat email-based OTP verification by tampering
Rate-limit bypass in Capgo versions prior to 12.128.2 lets remote unauthenticated attackers flood the channel_self endpo
Cross-tenant data poisoning in Supabase Capgo before 12.128.2 allows remote unauthenticated attackers to corrupt billing
Server-side privilege escalation in Capgo before 12.128.2 lets authenticated users holding build permissions abuse a pat
Unauthenticated information disclosure in Capgo before 12.128.2 lets remote attackers query the /functions/v1/channel_se
Account takeover in Capgo before 12.128.2 stems from a password-change endpoint that omits current-password validation (
Information disclosure in Capgo (Capacitor live-update/OTA platform) before 12.128.2 lets unauthenticated callers abuse
Unauthenticated information disclosure in Capgo before 12.128.2 lets remote attackers read organization RBAC role bindin
Cross-tenant authorization bypass in Capgo before 12.128.2 lets authenticated users impersonate another tenant's limited
Same weakness CWE-209 – Error Message Information Leak
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today