Logseq is vulnerable to a stored cross-site scripting (XSS). A malicious plugin can include a JavaScript payload in the "name" field of its "package.json" file, which is rendered using "innerHTML" without proper sanitization, allowing the execution of arbitrary code in the privileged host context. While only version v0.10.15 was tested and confirmed as vulnerable, status of other versions is unknown since this issue was not addressed by a patch.

The CISA Software Acquisition Guide Supplier Response Web Tool before 2025-12-11 was vulnerable to cross-site scripting via text fields. If an attacker could convince a user to import a specially-crafted JSON file, the Tool would load JavaScript from the file into the page. The JavaScript would execute in the context of the user's browser when the user submits the page (clicks 'Next').