Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads (CVE-2026-3416) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-3416

Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads

Answer in brief

CVE-2026-3416 records a Unknown severity vulnerability in Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads. The current sources do not mark it as known exploited. The current feed maps WSO2/WSO2 API Control Plane (generic), WSO2/WSO2 API Manager (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 3, 2026Updated Sep 3, 2026Source checked Sep 3, 2026First seen by HOL Sep 3, 2026Material review Sep 3, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps WSO2/WSO2 API Control Plane (generic), WSO2/WSO2 API Manager (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
WSO2/WSO2 API Control Planegeneric	>=4.5.0 <4.5.0.53	4.5.0.53
WSO2/WSO2 API Managergeneric	>=4.1.0 <4.1.0.253 \|\| >=4.2.0 <4.2.0.193 \|\| >=4.3.0 <4.3.0.104 \|\| >=4.4.0 <4.4.0.68 \|\| >=4.5.0 <4.5.0.52	4.1.0.253, 4.2.0.193, 4.3.0.104, 4.4.0.68, 4.5.0.52

Recommended response

Check inventory. Check lockfiles and deployed manifests for WSO2/WSO2 API Control Plane, WSO2/WSO2 API Manager.
Review the reported fix. Update WSO2/WSO2 API Control Plane to 4.5.0.53; WSO2/WSO2 API Manager to 4.1.0.253 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 3, 2026

Sources and claim methodology

Source referencesecurity.docs.wso2.com

Upstream source description

The API Publisher component previously used a non-cryptographic pseudorandom number generator (PRNG) to create shared secrets for Webhook HMAC validation. This PRNG lacks sufficient entropy for security-sensitive operations, allowing a sophisticated attacker to predict future secrets. This enables malicious actors to forge event payloads with valid HMAC signatures, bypassing the API Gateway's authenticity verification. Successful exploitation could allow an attacker to predict shared secrets used for Webhook HMAC validation and forge event payloads with valid signatures. This may enable bypassing API Gateway authenticity checks, leading to unauthorized event injection, data manipulation, or downstream system compromise.

Quoted source text, attributed separately from HOL analysis.