CVE-2026-52840
LOWCVE-2026-52840 is a low-severity (CVSS 2.7) Server-Side Request Forgery (SSRF) vulnerability in alextselegidis/easyappointments. O3 Security confirms whether CVE-2026-52840 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Easy!Appointments has server-side request forgery in CalDAV connection test that exposes the deployment's internal network
Blast Radius
alextselegidis/easyappointmentsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, Caldav::connect_to_server at application/controllers/Caldav.php:60 hands the request's caldav_url to a Guzzle REPORT call without scheme or host validation. A logged-in backend user (admin, provider, or secretary) reaches loopback, RFC1918, and link-local hosts on the deployment's network. The Guzzle exception path returns the upstream status code plus ~120 bytes of response body in the JSON message field (Caldav.php:74-78), so the SSRF is semi-blind. Version 1.6.0 contains a patch.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | alextselegidis/easyappointments | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for alextselegidis/easyappointments. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of alextselegidis/easyappointments has shipped for CVE-2026-52840 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-52840 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-52840. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-52840 in your dependencies?
O3 detects CVE-2026-52840 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.