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Capgo Build Upload Proxy Authorization Bypass via TUS Resource

Priority HIGH 71CWE-441Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Capgo (capgo.app) exposes a native build TUS upload proxy (supabase/functions/_backend/public/build/upload.ts) that authorizes a caller against a single build job identified by the supplied builder_job_id and validates only that job's stored upload_path, but then forwards the user-controlled TUS resource suffix taken from /build/upload/:jobId/* to the builder service while injecting Capgo's privileged builder API key. Because the forwarded suffix is never bound to the authorized job's upload_path or upload_session_key, a caller holding a valid 'all' or 'write' Capgo API key with app.build_native permission for one application can use its authorized proxy path for job A to write to the TUS upload resource of another job B, provided that resource suffix is known or exposed, corrupting that build's artifacts. All versions are affected; no patch was available at the time of advisory publication.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.003 22nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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

VendorProductAffected versionsFixed inStatusSource
Capgocapgo.appall versions—No fix listedCNA
  • capgo.app VendorCapgo Affected all versions Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-100625
  2. 2026-10-03 Alias added: GHSA-vp2f-59w8-7r7r

References

  • 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
See all 124 →

Sources