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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-3416
StatePUBLISHED
AssignerWSO2
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-03 13:05:37 UTC
Updated2026-09-03 17:50:15 UTC
DescriptionThe 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.

Risk And Classification

Primary CVSS: v3.1 5.9 MEDIUM from ed10eef1-636d-4fbe-9993-6890dfa878f8

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS: 0.002720000 probability, percentile 0.193200000 (date 2026-09-05)

Problem Types: CWE-330 | CWE-330 CWE-330: Use of Insufficiently Random Values

VersionSourceTypeScoreSeverityVector
3.1ed10eef1-636d-4fbe-9993-6890dfa878f8Secondary5.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
3.1CNACVSS5.9MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA WSO2 WSO2 API Manager unknown 4.1.0 custom Not specified
CNA WSO2 WSO2 API Manager affected 4.1.0 4.1.0.253 custom Not specified
CNA WSO2 WSO2 API Manager affected 4.2.0 4.2.0.193 custom Not specified
CNA WSO2 WSO2 API Manager affected 4.3.0 4.3.0.104 custom Not specified
CNA WSO2 WSO2 API Manager affected 4.4.0 4.4.0.68 custom Not specified
CNA WSO2 WSO2 API Manager affected 4.5.0 4.5.0.52 custom Not specified
CNA WSO2 WSO2 API Control Plane affected 4.5.0 4.5.0.53 custom Not specified

References

ReferenceSourceLinkTags
security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO... ed10eef1-636d-4fbe-9993-6890dfa878f8 security.docs.wso2.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Solutions

CNA: Follow the instructions given on https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5174/#solution

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