CVE-2026-17538 — Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress <= 5.6.9 - Authenticated (Subscriber+) Insecure Direct Object Reference to Arbitrary Customer PII Modification
The LatePoint - Appointment Booking & Reservation plugin for WordPress is vulnerable to Insecure Direct Object Reference in versions up to, and including, 5.6.9. This is due to the process_step_customer() function using is_user_logged_in() as the sole gate before merging POSTed customer data into an existing LatePoint customer, without any ownership checks. This makes it possible for authenticated attackers, with Subscriber-level access and above, to modify the personal information (first name, last name, email, phone, notes) of arbitrary LatePoint customers, and, when the contact_merge setting is 'phone', to overwrite the victim's email address and take over the account via a password reset.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
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.
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.
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.
- Identify exposed assets running the affected vendor/product/version combinations (Latepoint Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- 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.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Latepoint | Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress | ≤ 5.6.9 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored 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-639 · Authorization Bypass Through User-Controlled Key (IDOR)
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.15%
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.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · latepoint/appointment booking plugin – latepoint | calendar & scheduling for wordpress
- SSVC assessment updated
- Record published
- CVSS changed · 5.4
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-100163 Appointment Booking Plugin <= 5.7.2 - Unauthenticated Authentication Bypass to Customer Account Takeover via Insufficient Verification in create_wp_user_for_customer() username_exists Fallback 1d
- High CVE-2026-103366 Appointment Booking Plugin <= 5.7.3 - Insecure Direct Object Reference to Unauthenticated Sensitive Information Disclosure via 'booking[id]' and 'cart[id]' Parameters 1d
- Medium CVE-2026-103380 Appointment Booking Plugin <= 5.7.3 - Authenticated (Subscriber+) Sensitive Information Exposure in 'first_name' Parameter Template Re-expansion 1d
- High CVE-2026-96662 Appointment Booking Plugin <= 5.7.2 - Unauthenticated SQL Injection via 'booking[service_id]' Parameter 5d
- Medium CVE-2026-91050 Appointment Booking Plugin <= 5.7.2 - Insecure Direct Object Reference to Authenticated (Subscriber+) Unauthorized Booking Creation and Sensitive Information Disclosure via 'params[presets][order_item_id]' Parameter 5d
- High CVE-2026-104766 Appointment Booking Plugin <= 5.7.3 - Authenticated (Custom+) Privilege Escalation to 'settings[default_wp_role_for_customer]' Parameter 5d
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-2026-17538 is "Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress <= 5.6.9 - Authenticated (Subscriber+) Insecure Direct Object Reference to Arbitrary Customer PII Modification", rated Medium. It affects Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress (Latepoint); 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 0.15% 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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