CVE-2026-16540: Simply Schedule Appointments < 1.6.12.6 - Unauthenticated Appointment Data Disclosure and Mass Deletion via purge Endpoint
Noroxi assessment
Priority: Monitor (action score 30/100)
- Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.40% (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.
- Fixed version: Unknown Simply Schedule Appointments 1.6.12.6.
Low priority for now. Upgrade to Unknown Simply Schedule Appointments 1.6.12.6 or later.
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 Simply Schedule Appointments WordPress plugin before 1.6.12.6 does not correctly restrict a bulk appointment operation to the requester's own records, allowing unauthenticated users to retrieve the personal data of all appointments across the site and, on premium editions, to permanently delete them.
- Published
- Aug 2, 2026
- Updated
- Aug 26, 2026
- EPSS
- 0.4% · 35th percentile
- CWE
- CWE-863
Report tools
Action score
30
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- yes
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
Is Simply Schedule Appointments on your site?
WP Lens reads your site's plugin, theme and WordPress versions from the outside and matches them to known vulnerabilities. Works without an account.
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.
We use this product, ask for helpAffected 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.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (WPScan). Independent of NVD's CPE analysis and usually ahead of it.
Unknown Simply Schedule Appointments
- before 1.6.12.6affected · semver
Same product
unknown: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-16541Simply Schedule Appointments < 1.6.12.17 - Team Member+ User Email Disclosure via Users and Customers REST Endpoints26Monitor
- CVE-2026-15254Simply Schedule Appointments < 1.6.12.11 - Contributor+ Sensitive Data Disclosure via Admin Shortcode26Monitor
- CVE-2026-13400Simply Schedule Appointments < 1.6.12.4 - Unauthenticated Stored XSS via Booking Customer Information24Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Unknown Simply Schedule Appointments | 1.6.12.6 | Vendor (CNA) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:1 | 2026-07-22 |
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.
- First PoC-11 d
- Published
- TodayNov 13, 2026+103 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Suleyman Huseynovfinder
- WPScancoordinator
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-152541 days apartSimply Schedule Appointments < 1.6.12.11 - Contributor+ Sensitive Data Disclosure via Admin Shortcode26Monitor
Not on record for this CVE: patch commit or PR link · public bounty program.
Technical details
Attack conditions
- 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.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-863 · Incorrect AuthorizationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.