CVE-2026-6937· NVD / CVE Program· CNA Wordfence

Appointment Booking Calendar <= 1.6.11.8 - Missing Authorization to Unauthenticated Arbitrary Modification via Bulk Appointments REST API Endpoint

Noroxi assessment

Priority: Monitor (action score 21/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.63% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 1.6.11.8 due to the plugin not properly verifying that a user is authorized to perform an action via the bulk appointments REST API endpoint. This makes it possible for unauthenticated attackers to modify arbitrary appointment records including customer PII, payment status, and meeting URL fields, and to expose full customer PII from existing appointment records via the bulk endpoint response. The public nonce is a static, user-independent value present in the HTML source of any page hosting the [ssa_booking] shortcode, meaning any visitor who has viewed such a page can obtain it and target any appointment in the system without authentication.

MediumCVSS 5.3 · v3.1—No exploit No fix recorded

Published: May 28, 2026
Updated: Jun 17, 2026
EPSS: 0.6% · 49th percentile
CWE: CWE-862

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Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Wordfence: 5.3; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (Wordfence). Independent of NVD's CPE analysis and usually ahead of it.

croixhaug Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin
- up to and including 1.6.11.8affected · semver

Same product

croixhaug: all records

Other highest-scoring records for the same primary product.

CVE-2026-7797Appointment Booking Calendar <= 1.6.11.8 - Unauthenticated SQL Injection via 'append_where_sql' Parameter
30Monitor
CVE-2026-3658Appointment Booking Calendar <= 1.6.10.0 - Unauthenticated SQL Injection via 'fields' Parameter
30Monitor
CVE-2026-3045Appointment Booking Calendar <= 1.6.9.29 - Missing Authorization to Unauthenticated Sensitive Information Exposure via Settings REST API Endpoint
30Monitor

Published before and after this one in the same product

← EarlierCVE-2026-1704Mar 13, 2026 · Appointment Booking Calendar <= 1.6.9.29 - Insecure Direct Object Reference to Authenticated (Staff+) Sensitive Information Exposure
17Monitor
← EarlierCVE-2026-4807May 6, 2026 · Appointment Booking Calendar <= 1.6.10.6 - Unauthenticated Arbitrary Appointment View, Modification and Deletion
26Monitor
← EarlierCVE-2026-7493May 26, 2026 · Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.11.5 - Unauthenticated Denial of Service
21Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

winracefinder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-304576 days apartAppointment Booking Calendar <= 1.6.9.29 - Missing Authorization to Unauthenticated Sensitive Information Exposure via Settings REST API Endpoint
30Monitor
CVE-2026-480722 days apartAppointment Booking Calendar <= 1.6.10.6 - Unauthenticated Arbitrary Appointment View, Modification and Deletion
26Monitor
CVE-2025-13754160 days apartAppointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.9.16 - Missing Authorization to Unauthenticated Sensitive Information Exposure
21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).