Appointment Booking Calendar <= 1.4.05 - Authenticated (Subscriber+) Stored Cross-Site Scripting via 'vs_text_submitbtn' Parameter

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

The Appointment Booking Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'vs_text_submitbtn' parameter in all versions up to, and including, 1.4.05 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the attacker to be assigned as a calendar owner, a per-user grant that any administrator can extend to users as low as Subscriber level through the plugin's calendar list screen. Exploitation by attackers with subscriber-level access and above requires that an administrator has assigned the attacker's account as owner (`conwer`) of a calendar via the plugin's calendar list screen; the plugin's UI lists all registered users regardless of role, so a Subscriber can be assigned. On a default installation, where that is not configured, the vulnerability requires attackers with editor-level access and above.

Source published

28 Oct 2026 03:42:54 UTC

Source modified

29 Oct 2026 01:41:55 UTC

Observed here

29 Oct 2026 03:25:09 UTC

Source terms

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CVSS 3.1 · 6.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N