CVE-2026-110653 — Appointment Booking Plugin <= 5.7.4 - Unauthenticated Authentication Bypass via Race Condition on OTP Attempts Counter
The Appointment Booking Plugin – LatePoint | Calendar & Scheduling for WordPress plugin for WordPress is vulnerable to Authentication Bypass via Race Condition in all versions up to, and including, 5.7.4. This is due to a non-atomic read-modify-write on the OTP verification attempts counter in the `verifyOTP` function: the counter is incremented using a stale in-memory value with no conditional `WHERE attempts < 10` guard on the `UPDATE` and no `SELECT ... FOR UPDATE` row lock, creating a TOCTOU window that allows concurrent requests to bypass the 10-attempt lockout. This makes it possible for unauthenticated attackers — who know a target customer's registered email address or phone number — to fire concurrent requests to the `auth__verify_otp` endpoint, defeat the lockout cap, brute-force the 6-digit OTP code, and authenticate as the targeted LatePoint customer, gaining full access to their account, bookings, and personal data. The nonce check present on the endpoint (`otp_verify_otp_nonce`) does not mitigate this issue, as the nonce is publicly emitted by the unauthenticated `request_otp` and `resend_otp` endpoints and is trivially obtainable by any unauthenticated attacker prior to launching the race.
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
- Technical severity (critical)+10
- Automatable exploitation (SSVC)+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).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (authentication), 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 | ≤ 5.7.4 | 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 |
|---|---|---|---|---|---|
| 9.1 | CVSS 3.1 | Critical | 3.9 | 5.2 | security@wordfence.com via NIST National Vulnerability Database |
| 9.1 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.1 | CVSS 3.1 | Critical | — | — | Wordfence via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N (score shown at the top: security@wordfence.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
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).
- Review authentication logs: logins without MFA, anomalous sessions and recently created accounts.
Timeline
What happened to this CVE, newest first.
- 2026
- SSVC assessment updated
- Affected products added · latepoint/appointment booking plugin – latepoint | calendar & scheduling for wordpress
- Record published
- CVSS changed · 9.1
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 17, 2026 – Oct 18, 2026
- 1× Official description updated · Oct 17, 2026 – Oct 17, 2026
References
9 on the record
- github.com/advisories/GHSA-3xwr-ghgc-2994
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.4/lib/helpers/otp_helper.php
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.4/lib/controllers/auth_controller.php
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.4/lib/controllers/auth_controller.php
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.4/lib/helpers/otp_helper.php
- www.wordfence.com/threat-intel/vulnerabilities/id/61fbc1dd-06c9-409b-8cad-3f350b38dfc3
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.4/lib/models/model.php
- plugins.trac.wordpress.org/browser/latepoint/tags/5.7.5/lib/helpers/otp_helper.php
- nvd.nist.gov/vuln/detail/CVE-2026-110653
Elsewhere on this site
Related CVEs (same products)
- Low CVE-2026-111602 Appointment Booking Plugin <= 5.7.4 - Unauthenticated Sensitive Information Disclosure via ORM Operator Injection in 'customer[uuid]' Parameter 1d
- 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 4d
- 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 4d
- Medium CVE-2026-103380 Appointment Booking Plugin <= 5.7.3 - Authenticated (Subscriber+) Sensitive Information Exposure in 'first_name' Parameter Template Re-expansion 4d
- High CVE-2026-96662 Appointment Booking Plugin <= 5.7.2 - Unauthenticated SQL Injection via 'booking[service_id]' Parameter 8d
- 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 8d
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 FIRST EPSS score.
- 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-2026-110653 is "Appointment Booking Plugin <= 5.7.4 - Unauthenticated Authentication Bypass via Race Condition on OTP Attempts Counter", rated Critical. 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 9.1 describes technical severity. 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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