CVE-2026-88861 — Capgo AAL1 Session MFA Bypass via Direct RBAC Authorization
Capgo (Cap-go/capgo.app) contains an authentication bypass affecting all versions (no patched version available at time of publication). The Edge authorization path allows a password-only Supabase aal1 session to exercise privileged RBAC permissions even when the account has a verified MFA factor that has not been used for the session: the Edge JWT middleware (foundJWT() in supabase/functions/_backend/utils/hono_middleware.ts) accepts the JWT without validating its assurance level, and the direct RBAC path (checkPermission()/checkPermissionPg() in supabase/functions/_backend/utils/rbac.ts calling public.rbac_check_permission_direct()) authorizes by user ID without passing or checking the session aal, unlike the public.verify_mfa() control which correctly requires aal2. An attacker who knows only the victim's password can therefore authenticate, mint a persistent app-scoped app_admin API key that remains valid after the aal1 session is logged out, and perform privileged operations such as modifying production OTA channel configurations (validated by changing a public production channel from bundle 1.0.0 to 1.0.1), defeating the protection provided by MFA.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Capgo Capgo.app).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (authentication), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.7 | CVSS 4.0 | High | — | — | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 8.7 | CVSS 4.0 | High | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
| 8.3 | CVSS 3.1 | High | 2.8 | 5.5 | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 8.3 | CVSS 3.1 | High | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L (score shown at the top: disclosure@vulncheck.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-288 · Authentication Bypass Using an Alternate Path or Channel
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · cap-go/capgo.app
- SSVC assessment updated
- Record published
- CVSS changed · 8.3
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-100629 Capgo backend before 12.127.5 Privilege Escalation via role_bindings PATCH 19d
- Medium CVE-2026-100621 capgo.app Content-Lock Bypass via r2-direct Bundle Mutation 19d
- High CVE-2026-100622 capgo.app through 12.129.0 Cache Restoration of Deleted Bundles 19d
- High CVE-2026-100623 Capgo Authentication Bypass via Direct PostgREST org_users Table Write 19d
- Medium CVE-2026-100624 Capgo.app before 12.264.5 Upload Expiry Bypass via build upload 19d
- Medium CVE-2026-100626 capgo through 12.128.2 IDOR via PUT /app icon endpoint 19d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-88861 is "Capgo AAL1 Session MFA Bypass via Direct RBAC Authorization", rated High. It affects Capgo.app (Capgo); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.3 describes technical severity. EPSS 0.52% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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