CVE-2026-3416

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

State
Published
Severity
5.9 Medium
Published
Sep 3, 2026
Updated
Sep 3, 2026
Reserved
Mar 1, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.15.9 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:NWSO2

Weaknesses

  • CWE-330 Use of Insufficiently Random Values

Affected Products

ProductVersions
WSO2 API ManagerWSO2
  • before 4.1.0Unknown
  • 4.1.0 to before 4.1.0.253Affected
  • 4.2.0 to before 4.2.0.193Affected
  • 4.3.0 to before 4.3.0.104Affected
  • 4.4.0 to before 4.4.0.68Affected
  • 4.5.0 to before 4.5.0.52Affected
WSO2 API Control PlaneWSO2
  • 4.5.0 to before 4.5.0.53Affected

References

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