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.

Project Subscriptions

Vendors Products
Wso2 Api Control Plane Subscribe
Wso2 Api Manager Subscribe
Advisories

No advisories yet.

Fixes

Solution

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


Workaround

No workaround given by the vendor.

History

Thu, 03 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 03 Sep 2026 12:45:00 +0000

Type Values Removed Values Added
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.
Title Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads
First Time appeared Wso2
Wso2 wso2 Api Control Plane
Wso2 wso2 Api Manager
Weaknesses CWE-330
CPEs cpe:2.3:a:wso2:wso2_api_control_plane:*:*:*:*:*:*:*:*
cpe:2.3:a:wso2:wso2_api_manager:*:*:*:*:*:*:*:*
Vendors & Products Wso2
Wso2 wso2 Api Control Plane
Wso2 wso2 Api Manager
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: WSO2

Published:

Updated: 2026-09-03T12:55:15.634Z

Reserved: 2026-03-01T18:48:54.097Z

Link: CVE-2026-3416

cve-icon Vulnrichment

Updated: 2026-09-03T12:55:12.524Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-03T13:05:37.847

Modified: 2026-09-03T17:50:15.353

Link: CVE-2026-3416

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-03T13:30:04Z

Weaknesses