Do Son 
TL;DR
WSO2 patched seven vulnerabilities across its API platform, including WSO2 API Manager, in June 2026. The worst, CVE-2026-5430, scores a maximum 10 and bypasses JWT authentication. The rest cover privilege escalation, file upload, SQL injection, denial of service, and SSRF.
Why It Matters
WSO2 software sits at the front of many enterprise APIs. It handles authentication, traffic shaping, and gateway duties for large deployments. Banks, telcos, and government agencies run it in production. Therefore, a single flaw can expose every API behind it. The flagship bug, CVE-2026-5430, reaches a perfect 10 in multi-tenant setups. It lets an attacker bypass JWT checks and seize accounts, including admin ones. Several other WSO2 API Manager flaws also lead to full administrative takeover. The stakes climb fast for any internet-facing install, since these gateways often guard sensitive backend services. A single takeover can cascade into the systems the gateway protects.
How the Attack Works
Authentication Bypass (CVE-2026-5430)
The platform accepts a JWT signed with an unsupported algorithm. As a result, an attacker can forge a token and gain access. WSO2 scores this issue 10 in multi-tenant mode and 9.8 in single-tenant mode. The vendor calls the impact a full account takeover. No login or user interaction is required, which raises the urgency.
Privilege Escalation (CVE-2026-1728, CVE-2026-4052)
A low-privileged token can reach Admin and System REST APIs. That access lets a normal user climb to administrator. CVE-2026-1728 carries a 9.8 score and needs no special setup. CVE-2026-4052 affects deployments that run Identity Server as a Resident Key Manager with shared databases. There, a self-registered user can pull a token and invoke privileged APIs.
File Upload and SQL Injection (CVE-2026-3418, CVE-2026-2613)
An authenticated publisher can upload a file to a chosen location. Depending on how the server handles it, that upload may run as code. WSO2 rates this file upload bug 9.1. A separate flaw lets an authenticated admin run blind SQL injection through the Admin REST API. That bug, scored 8.7, can expose database contents or disrupt the service.
Denial of Service and SSRF (CVE-2026-4249, CVE-2026-2053)
An unauthenticated attacker can inject crafted JSON into throttling events. This triggers a persistent denial of service on the API Gateway, scored 8.6. A separate unauthenticated SSRF bug abuses WS-Addressing headers. It can force the server to send requests to internal resources, which exposes services that sit behind the firewall.
Affected Versions
The flaws affect WSO2 API Manager from version 4.6.0 down to 3.1.0, depending on the bug. They also touch API Control Plane, Traffic Manager, and Universal Gateway at 4.5.0 and 4.6.0. The CVSS 10 auth bypass spans API Manager 4.1.0 through 4.6.0. The SSRF flaw hits older API Manager builds, including 3.1.0 and 3.2.0. The exact product and version list varies per advisory, so check each one against your deployment.
Patch and Mitigation
WSO2 published fixes for every issue. Community users can apply the public pull requests or move to a fixed release. Subscription holders should update to the listed update level or higher. The CVE-2026-4052 fix needs extra steps for the Identity Server connector, including jar replacements and a restart. You can review all details on the official WSO2 2026 security advisories page. No public proof-of-concept and no in-the-wild exploitation have been confirmed. Still, these bugs target widely used API infrastructure, so patch quickly. Keep admin and system endpoints off untrusted networks until you finish. Prioritize the CVSS 10 auth bypass, since it needs no credentials at all.
Support Our Threat Intelligence
If you find our CVE report and cybersecurity news helpful, consider supporting our work.
Buy Me a Coffee
PayPal
