Capgo - Plan Bypass via Unrestricted Attachment Upload Endpoint
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.
Summary
Capgo before 12.128.2 fails to enforce plan/quota restrictions on the /files/upload/attachments endpoint, allowing plan-blocked apps to create publicly readable R2 objects. Attackers can upload arbitrary attachments using upload-scoped API keys that bypass plan checks, persist outside normal bundle metadata, and survive app deletion, enabling storage and bandwidth abuse.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Capgo (Capgo) Fixed in 12.128.2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Capgo 12.128.2
6 records Highest priority Priority HIGH 2 HIGH, 3 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-40644 Capgo - Information Disclosure via get_orgs_v7 RPC EndpointPriority HIGH 77
- TI-2026-40670 Capgo - Authentication Bypass in Password Change via Missing Current Password ValidationPriority HIGH 73
- TI-2026-40700 Capgo - Channel Configuration Mutation via Write-Scoped API KeysPriority MEDIUM 64
Timeline
- 2026-10-02 Threatist record created from CVE-2026-56309
- 2026-10-03 Alias added: GHSA-644w-64m3-9c8v
References
More Capgo vulnerabilities
- TI-2026-40602 Capgo - Unauthenticated API Key Generation via Client-Side Parameter Manipulation CVSS 4.0CRITICAL 9.3
- TI-2026-40473 Cap-go - Account Lockout via 2FA Misconfiguration on Unverified Email CVSS 4.0CRITICAL 9.3
- TI-2026-40465 Cap-go - OTP Bypass via Response Manipulation in Email Verification CVSS 4.0CRITICAL 9.3
- TI-2026-64782 capgo.app through 12.129.0 Cache Restoration of Deleted Bundles CVSS 4.0HIGH 8.7
- TI-2026-40704 Capgo - Unauthenticated Organization Existence Enumeration via rescind_invitation RPC CVSS 4.0HIGH 8.7
- TI-2026-40689 Capgo - Rate Limit Bypass via User-Controlled device_id Parameter CVSS 4.0HIGH 8.8
Sources
- CVE-2026-56309 · CVE Program
- CVE-2026-56309 · NVD
- FIRST EPSS
- GHSA-644w-64m3-9c8v · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences