---
id: "CVE-2026-17358"
page: "https://infrastack.ai/live/CVE-2026-17358"
kind: "vulnerability"
aliases: ["CVE-2026-17358"]
title: "IBM API Connect: cross-tenant authentication bypass by authenticated users"
severity: "high"
cvss: 8.2
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "IBM API Connect", "fixed": ["10.0.8.13"], "affected": ">= 10.0.8.0, <= 10.0.8.12", "ecosystem": "vendor"}, {"name": "IBM API Connect V12 OnPrem", "fixed": ["12.1.1.3"], "affected": ">= 12.1.0.0, <= 12.1.1.2", "ecosystem": "vendor"}]
ecosystems: []
tags: ["api-gateway", "ibm-api-connect", "infrastructure", "multi-tenant"]
not_affected_if: ["outside-affected-versions", "single-tenant-deployment"]
published_at: "2026-11-07T05:18:47+00:00"
first_seen_at: "2026-11-07T05:46:05+00:00"
updated_at: "2026-11-07T06:13:12+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-17358", "first_seen_at": "2026-11-07T05:46:05+00:00"}, {"source": "analyst", "url": "https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-41", "first_seen_at": "2026-11-07T06:13:12+00:00", "cites": ["https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-41", "https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39"]}]
exploit_sources: []
---

# IBM API Connect: cross-tenant authentication bypass by authenticated users

Link for people: https://infrastack.ai/live/CVE-2026-17358 (this .md is for agents)

IBM API Connect versions 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 do not isolate authentication checks between tenants. A logged-in user from one tenant can be accepted by another tenant, which can expose that tenant's resources.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:IBM API Connect affected >= 10.0.8.0, <= 10.0.8.12 fixed 10.0.8.13
- vendor:IBM API Connect V12 OnPrem affected >= 12.1.0.0, <= 12.1.1.2 fixed 12.1.1.3

## How to check

- Check your installed API Connect version: affected are 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 (IBM lists V12 OnPrem).
- Fixed in 10.0.8.13 and 12.1.1.3.
- Multi-tenant or multi-organization shared instances are the main concern; IBM's bulletin does not say whether single-tenant setups are affected, so upgrade anyway.

## Fix

Upgrade IBM API Connect 10.0.8.x to 10.0.8.13, or 12.1.x to 12.1.1.3 (via IBM Fix Central). IBM lists no workarounds or mitigations.

## Timeline

- 2026-11-07T05:46:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-17358
- 2026-11-07T06:13:12+00:00 analyst https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-41 — IBM bulletins (10.0.8.13 and v12.1.1.3) list CVE-2026-17358, CVSS 8.2, fix versions, no workarounds. Single-tenant exposure not stated by IBM. node/7295637 duplicates the -41 bulletin. No exploitation/PoC in sources; social not searched.

## Documents

- [advisory] IBM Security Bulletin: Multiple Vulnerabilities in IBM API Connect (10.0.8.13) https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-41
- [advisory] IBM Security Bulletin: Multiple Vulnerabilities in IBM API Connect (v12.1.1.3) https://www.ibm.com/support/pages/security-bulletin-multiple-vulnerabilities-ibm-api-connect-39

## From the sources

IBM API Connect 10.0.8.0 through 10.0.8.12 and 12.1.0.0 through 12.1.1.2 could allow a remote authenticated attacker to bypass authentication across tenants due to improper authentication. Authentication checks are not sufficiently isolated between tenants, which could allow a user from one tenant to be accepted by another.

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