Easy!Appointments disable_booking_message rendered as raw HTML on public booking page — Stored XSS

published 2026-07-14 3 mo ago modified 2026-10-24 15 d ago also GHSA-996f-334j-67g7 , EUVD-2026-43705

cvss: 2.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits: 0; none known

Easy!Appointments is a self hosted appointment scheduler. Versions prior to 1.6.0 allow administrators to define a custom "booking disabled" message through the booking settings page. That value is stored in the `disable_booking_message` setting via a rich-text editor and later passed directly to the public `booking_message` view without escaping or sanitization. An authenticated administrator can store HTML or JavaScript in this field, enable disabled-booking mode, and trigger stored XSS in every unauthenticated visitor who opens the public booking page. Version 1.6.0 fixes the issue.

Patch / fix

links 2

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 3 mo ago (2026-07-14)

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-996f-334j-67g7 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	2.6	CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:N/I:L/A:N
GitHub	3.1	2.6	CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:N/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
packagist	alextselegidis/easyappointments	<=1.5.2	no fix listed

Affected products

alextselegidis easyappointments

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary