CVE-2026-3416Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads
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It affects WSO2 API Manager and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-330
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- WSO2
- NVD analysis
- Analyzed
- Record last updated
- Sep 3, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
WSO2 WSO2 API Manager wso2:api_manager (from the name) | before 4.1.0 status unknown; from 4.1.0 before 4.1.0.253; from 4.2.0 before 4.2.0.193; from 4.3.0 before 4.3.0.104; from 4.4.0 before 4.4.0.68; from 4.5.0 before 4.5.0.52 | CNA record |
WSO2 WSO2 API Control Plane wso2:api_control_plane (from the name) | from 4.5.0 before 4.5.0.53 | CNA record |
wso2 api_control_plane wso2:api_control_plane | from 4.5.0 before 4.5.0.53 | NVD |
wso2 api_manager wso2:api_manager | from 4.1.0 before 4.1.0.253; from 4.2.0 before 4.2.0.193; from 4.3.0 before 4.3.0.104; from 4.4.0 before 4.4.0.68; from 4.5.0 before 4.5.0.52 | NVD |
References
- https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5174/vendor-advisory, patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.