CVE-2026-52839: Easy!Appointments appointments/store and appointments/update allow cross-provider appointment injection — Authorization Bypass
Noroxi assessment
Priority: Monitor (action score 13/100)
- 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: 0.17% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: alextselegidis/easyappointments (Packagist) 1.6.0.
Low priority for now. Upgrade to alextselegidis/easyappointments (Packagist) 1.6.0 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
Easy!Appointments is a self hosted appointment scheduler. Versions prior to 1.6.0 correctly filter provider-scoped appointments in the `appointments/search` response, proving that provider isolation is an intended security boundary. However, the direct mutation endpoints `appointments/store` and `appointments/update` only check generic appointment privileges and never verify that the submitted `id_users_provider` belongs to the current session. A normal authenticated provider can inject new appointments into another provider's schedule via `store`, or reassign existing appointments into a foreign provider's calendar via `update`. The `store` path contains an additional write-before-crash bug: the unauthorized row is committed to the database before the controller crashes on a type error, so the attacker receives an error response while the foreign appointment is already persisted. Version 1.6.0 patches the issue.
- Published
- Jul 14, 2026
- Updated
- Oct 24, 2026
- EPSS
- 0.1% · 7th percentile
- CWE
- CWE-639
Report tools
Action score
13
Monitor
Low priority for now.
- CVSS
- 13 / 40 · 3.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.1%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 3.3
- 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.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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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.
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 (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
alextselegidis easyappointments
- < 1.6.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Packagist | alextselegidis/easyappointments | before 1.6.0 | 1.6.0 |
Same product
alextselegidis: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-108758Easy!Appointments through 1.6.0 Authorization Bypass via booking/register Endpoint35Monitor
- CVE-2026-55651Easy!Appointments Vulnerable to Appointments Takeover via Excessive Data Exposure28Monitor
- CVE-2026-52837Easy!Appointments has unauthenticated customer PII disclosure on booking reschedule page27Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-52838Jul 14, 2026 · Easy!Appointments disable_booking_message rendered as raw HTML on public booking page — Stored XSS10Monitor
- Later →CVE-2026-52840Jul 14, 2026 · Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment's internal network10Monitor
- Later →CVE-2026-52841Jul 14, 2026 · Easy!Appointments: Authorization bypass in Google OAuth provider binding lets any backend user rebind a peer provider's Google sync12Monitor
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 |
|---|---|---|
| Packagist:alextselegidis/easyappointments | 1.6.0 | Package registry (OSV) |
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.
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.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-10875889 days apartEasy!Appointments through 1.6.0 Authorization Bypass via booking/register Endpoint35Monitor
- CVE-2026-528410 days apartEasy!Appointments: Authorization bypass in Google OAuth provider binding lets any backend user rebind a peer provider's Google sync12Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-639 · Authorization Bypass Through User-Controlled KeyCVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N
nvd-secondary
Root cause
The endpoint fetches the record by the ID sent in the request, but never checks whether the record belongs to the requesting user.
The bug in code
The whole CWE-639 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const invoice = await Invoice.findById(req.params.id);
res.json(invoice);Fixed
const invoice = await Invoice.findOne({
id: req.params.id,
ownerId: req.user.id,
});
if (!invoice) return res.sendStatus(404);
res.json(invoice);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
- Fix✗ → ✓
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References
Show all references (1 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.