CVE-2026-39400

Cronicle prior to 0.9.119 concatenates the attacker-controlled item.user.full_name value into HTML in the administrator Activity Log (htdocs/js/pages/admin/Activity.js) without applying encode_entities and inserts the result through this.div.html. The bundled pixl-server-user input filter can be bypassed by a tag containing a line break because its regular expression does not match newlines. An authenticated non-administrator can update their own name through /api/user/update, and when free_accounts is enabled an anonymous attacker can plant the name during self-registration. The stored name executes script in an administrator's session when the Activity Log is opened, enabling administrator takeover and subsequent command execution. This issue is fixed in version 0.9.119.

In Cronicle prior to 0.9.121, a non-administrator user or scoped API key with `create_events` and `run_events` privileges can inject top-level `uid` and `gid` fields through `/api/app/create_event` or `/api/app/update_event`. In `lib/api.js`, `requireValidEventData` uses `validateOptionalParams` as a partial allow-list that silently passes unknown keys, storing the injected fields verbatim. In `lib/job.js`, `launchJob` copies the whole event into the job, and a plugin `uid` overrides the event `uid` only when the plugin defines one. The default `shellplug` and `urlplug` plugins do not define a `uid`, so the event-controlled identity survives into child-process launch.

Cronicle before version 0.9.111 has a vulnerability where child processes can modify the parent event's configuration via the update_event key in JSON output without any authorization check. This allows a low-privilege user who can create and run events to change any event property, including webhook URLs and notification emails.