CVE Intelligence
Medium Access control

CVE-2026-11821 — Eventin <= 4.1.17 - Missing Authorization to Authenticated (Subscriber+) Notification Flow Management via notification-flow REST API Endpoint

The Eventin – Event Calendar, Event Registration, Tickets & Booking (AI Powered) plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.1.17. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to view, create, update, clone, and delete notification flow event automation workflows that should be restricted to administrators.

Published Sep 9, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Wordfence

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+1
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

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

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.19%
ahead of 8% of scored CVEs · Oct 15, 2026
Affects
Arraytics
Eventin – Event Calendar, Tickets, Registration, Booking & WooCommerce
CVSS base
5.4
Medium · 2 source(s)

CISA SSVC assessment CISA

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

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Arraytics Eventin – Event Calendar, Tickets, Registration, Booking & WooCommerce).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Arraytics Eventin – Event Calendar, Tickets, Registration, Booking & WooCommerce ≤ 4.1.17 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

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

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Every base score collected

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

ScoreVersionSeverityExpl.ImpactScored by
5.4 CVSS 3.1 Medium 2.8 2.5 security@wordfence.com via NIST National Vulnerability Database
5.4 CVSS 3.1 Medium — — Wordfence via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N (score shown at the top: security@wordfence.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-862 · Missing Authorization

Other CVEs with this weakness →

Detection

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

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Audit administrative actions and access to resources outside each user’s normal pattern.
web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · arraytics/eventin – event calendar, tickets, registration, booking & woocommerce
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 5.4
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 9, 2026 · Wordfence

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

4 on the record

Elsewhere on this site

Arraytics
every CVE for this vendor
Access control
same class
CWE-862
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-75983 Eventin – Event Calendar, Tickets, Registration, Booking & WooCommerce <= 4.1.23 - Authenticated (Subscriber+) Privilege Escalation via map_meta_cap Filter Sep 15, 2026
  • CVE-2026-15402 Eventin <= 4.1.23 - Authenticated (Custom+) Stored Cross-Site Scripting via 'etn_shedule_objective' schedule_slot Parameter Sep 15, 2026
  • CVE-2026-15398 Eventin – Event Calendar, Event Registration, Tickets & Booking (AI Powered) <= 4.1.22 - Authenticated (Subscriber+) Missing Authorization to Order Completion / Free Ticket Redemption Sep 9, 2026
  • CVE-2026-15406 Eventin <= 4.1.22 - Authenticated (Custom+) Local File Inclusion via 'event_layout' Parameter Sep 9, 2026
  • CVE-2026-15667 Eventin <= 4.1.22 - Authenticated (Contirbutor+) Local File Inclusion via 'event_layout' Parameter Sep 9, 2026
  • CVE-2026-12956 Eventin <= 4.1.22 - Missing Authorization to Unauthenticated Arbitrary Order Creation and Status Manipulation via 'status' Parameter Sep 9, 2026

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 fixed version, patch or mitigation documented.
  • 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 record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-11821 is "Eventin <= 4.1.17 - Missing Authorization to Authenticated (Subscriber+) Notification Flow Management via notification-flow REST API Endpoint", rated Medium. It affects Eventin – Event Calendar, Tickets, Registration, Booking & WooCommerce (Arraytics); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.4 describes technical severity. EPSS 0.19% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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