Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2026-5430

WSO2 Universal Gateway Authentication Bypass Authentication Bypass

WSO2 / WSO2 Universal Gateway · affected before 4.5.0.57

View live feed Monitor via API Watch CVE-2026-5430
Severity
CVSS 10.0 · Critical
Confidence
High
Exploit status
Exploited in the wild
EPSS
0.3%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-5430 is an unauthenticated vulnerability affecting WSO2 WSO2 Universal Gateway and 4 other products. The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

WSO2 / WSO2 Universal Gateway affected before 4.5.0.57.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

WSO2 Universal Gateway Authentication Bypass Authentication Bypass

The JWT authentication mechanism accepts tokens signed with algorithms other than those explicitly configured or supported. This allows an attacker to craft a JWT with an unsupported algorithm, which is then incorrectly validated, leading to unauthorized access.

Successful exploitation of this vulnerability may result in unauthorized access to the system, including the potential compromise of administrative accounts and full account takeover. The CVSS score is adjusted to 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) in single-tenant deployments, reflecting that the impact is contained within a single security authority boundary.

WSO2 Affected
WSO2 Universal Gateway
Before 4.5.0.57 Before 4.6.0.21
WSO2 Affected
WSO2 Traffic Manager
Before 4.5.0.56 Before 4.6.0.21
WSO2 Affected
WSO2 API Control Plane
Before 4.5.0.58 Before 4.6.0.22
WSO2 Affected
WSO2 API Manager
Before 4.1.0.257 Before 4.2.0.197 Before 4.3.0.108 Before 4.4.0.72 Before 4.5.0.57 Before 4.6.0.21
WSO2 Affected
WSO2 Carbon API Manager Rest API Utility org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util
Before 9.20.74.401 Before 9.28.116.417 Before 9.29.120.236 Before 9.30.67.167 Before 9.31.86.158 Before 9.32.147.59
WSO2 Unaffected
WSO2 Carbon API Manager Rest API Utility org.wso2.carbon.apimgt:org.wso2.carbon.apimgt.rest.api.util
Through *
View vendor advisory (opens in new tab)
Published
06 Aug 2026
Exploitation Reported
16 Sep 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

TheHackerNews

Recorded 16 Sep 2026

A trusted third party reported exploitation.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
TheHackerNews First 2026-09-16 05:18 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

10.0 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

EPSS

0.3%

Weaknesses

Improper Verification of Cryptographic Signature CWE-347

Recent mention · TheHackerNews

Active Exploitation Attempts Target WSO2 API Manager JWT Bypass With Forged Admin Tokens

A critical security flaw in WSO2 API Manager has come under active exploitation in the wild, according to findings from watchTowr. The vulnerability, tracked as CVE-2026-5430 (CVSS score: 9.8/10.0), is a case of improper verification of a cryptographic signature that could...

Read full advisory

Timeline

From disclosure to observed exploitation

  1. 05:18 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  2. 00:00 UTC

    Added to the Previdian watchlist

    Pro and Enterprise Watch users had 1 month of early warning before Previdian confirmed it as a KEV.

  3. 07:33 UTC

    CVE published

    Vulnerability disclosed publicly

  4. 16:11 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-5430

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-5430",
  "confidence": "High",
  "cvss_score": 10.0,
  "cvss_estimated": false,
  "epss_score": 0.00321,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}