CVE-2026-88861: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-3rq3-733w-v2c4
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CVSS 8.3
CWE-288
Published
Advisory Summary

CVE-2026-88861 is a HIGH (CVSS 8.3) security vulnerability vulnerability (CWE-288: Authentication Bypass Using an Alternate Path or Channel) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product requires authentication, but the product has an alternate path or channel that does not require authentication.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-88861 at a Glance

CVE Identifier CVE-2026-88861
GHSA Identifier GHSA-3rq3-733w-v2c4
Severity HIGH
CVSS v3.1 Base Score 8.3
CWE Classification CWE-288: Authentication Bypass Using an Alternate Path or Channel
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2026-88861

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-88861, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-288: Authentication Bypass Using an Alternate Path or Channel, where the product requires authentication, but the product has an alternate path or channel that does not require authentication. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Cap-go/capgo.app/security/advisories/GHSA-9435-5xw9-v29h
NVD — CVE-2026-88861 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-88861
www.vulncheck.com/advisories/capgo-aa... WEB
https://www.vulncheck.com/advisories/capgo-aal1-session-mfa-bypass-via-direct-rbac-authorization

Frequently Asked Questions

What is CVE-2026-88861?
CVE-2026-88861 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-288: Authentication Bypass Using an Alternate Path or Channel.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-88861?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-88861?
CVE-2026-88861 has a CVSS v3.1 base score of 8.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L.
What CWE is associated with CVE-2026-88861?
CVE-2026-88861 is classified under CWE-288: Authentication Bypass Using an Alternate Path or Channel (The product requires authentication, but the product has an alternate path or channel that does not require authentication.).
How can I check Maven dependencies for CVE-2026-88861?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-3rq3-733w-v2c4",
  "modified" : "2026-09-10T15:33:16Z",
  "published" : "2026-09-10T15:33:16Z",
  "aliases" : [ "CVE-2026-88861" ],
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Cap-go/capgo.app/security/advisories/GHSA-9435-5xw9-v29h"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-88861"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/capgo-aal1-session-mfa-bypass-via-direct-rbac-authorization"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-288" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-10T14:17:11Z"
  }
}