Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-3416. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-3416 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

7 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-3416 using CVSS 5.9, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

Workarounds are not confirmed from current sources. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumCryptographypublic exploit

CVE-2026-3416

CVE-2026-3416 — Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads

Q: What is CVE-2026-3416?

CVE-2026-3416 is Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads. The supplied enrichment data classifies it as Cryptography mapped to CWE-330 CWE-330.

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.

Published Sep 3, 2026Updated Sep 3, 2026Sources: NVD, WSO2 (CNA), GitHub, GitHub Security Advisory, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

WSO2

7 products listed

CVSS base

5.9

medium

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

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

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
WSO2	WSO2 API Manager	0 to < 4.1.0	Vulnerable
WSO2	WSO2 API Manager	4.1.0 to < 4.1.0.253	Vulnerable
WSO2	WSO2 API Manager	4.2.0 to < 4.2.0.193	Vulnerable
WSO2	WSO2 API Manager	4.3.0 to < 4.3.0.104	Vulnerable
WSO2	WSO2 API Manager	4.4.0 to < 4.4.0.68	Vulnerable
WSO2	WSO2 API Manager	4.5.0 to < 4.5.0.52	Vulnerable
WSO2	WSO2 API Control Plane	4.5.0 to < 4.5.0.53	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

None

Confidentiality

High

Integrity

None

Scope

Unchanged

Attack Complexity

High

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.9	CVSS 3.1	medium	2.2	3.6	CNA, WSO2 (CNA), GHSA

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

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-330 · Use of Insufficiently Random Values

Other
Bypass Protection Mechanism
Gain Privileges or Assume Identity

Mitigation: Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds. In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts. Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a random enough number.

Weakness & attack patterns

CWE-330

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-59 · Session Credential Falsification through PredictionCAPEC-485 · Signature Spoofing by Key RecreationCAPEC-112 · Brute Force

T1110Brute Force
T1552.004Unsecure Credentials: Private Keys

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable WSO2 API Manager, WSO2 API Control Plane.
Monitor for scanner or exploit-pattern traffic after 7 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 5.9 (AV:N)
Sep 3, 2026 · NVD
Initial · CVE published
Sep 3, 2026 · NVD
Added · GHSA-x3mw-fvm5-jwf4 published (medium)
Sep 3, 2026 · GitHub Security Advisory
CVE published by MITRE.
Sep 3, 2026 · SOCRadar CTI

References

3 on the record

security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5174/
Vendor Advisory
nvd.nist.gov/vuln/detail/CVE-2026-3416
NVD
github.com/advisories/GHSA-x3mw-fvm5-jwf4
Exploit, Third Party Advisory

Elsewhere on this site

WSO2every CVE for this vendor
Cryptographysame class
CWE-330other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-3416 is Predictable Pseudorandom Number Generation via Webhook HMAC Secret Generation in Multiple WSO2 Products Allows Forged Event Payloads, a medium vulnerability affecting WSO2 API Manager, WSO2 API Control Plane from WSO2. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-3416. Public exploit evidence is: 7 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.9 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.