VulnerabilityDeferred

CVE-2026-52841

The peer's appointments then sync into the attacker's calendar with each customer's name and email attached as attendee data.

LOW 3.1EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

Description

Easy!Appointments is a self hosted appointment scheduler. In versions prior to 1.6.0, `Google::oauth` at `application/controllers/Google.php:278` stores its URL-supplied `provider_id` in the session, and `oauth_callback` saves the issued Google OAuth token against that row without checking the caller owns the provider. Any logged-in backend user (admin, provider, or secretary) rebinds a peer provider's Google sync to a Google account they control. The peer's appointments then sync into the attacker's calendar with each customer's name and email attached as attendee data. Version 1.6.0 patches the issue.

CVSS 3.1: 3.1 LOWCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:N
EPSS: 0.21% probability · 11th percentile
CISA KEV: Not listed
Weakness: CWE-639
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.