sheshbabu zen EUVD-2026-87113

Requires an authenticated low-privilege account on a running self-hosted zen instance (PR:L) and the ability to save note content that reaches the Note Editor, which renders it through React's dangerouslySetInnerHTML in features/notes/NotesEditor.jsx without sanitization. Execution depends on a user subsequently viewing the malicious note in a browser (UI:P / passive interaction). Limiting factors: authentication is needed, the app is a single-/personal-user self-hosted tool so payloads often execute in the same account that stored them, no known fixed version exists, and there is no confidentiality or availability impact per the vector.

This is a genuinely low-to-moderate priority issue whose signals are largely consistent. The vendor-supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N, score 5.1) describes a stored/DOM cross-site scripting flaw reachable over the network but requiring an authenticated low-privilege user (PR:L) and passive victim interaction (UI:P), with only limited integrity impact (VI:L) and no confidentiality or availability impact. The E:P attack maturity metric aligns with the confirmed public exploit (a Notion write-up demonstrating stored XSS). There is NO CISA KEV listing and NO EPSS score was provided, so there is no evidence of active or widespread exploitation - the exploitation status is best described as publicly available exploit code without confirmed in-the-wild use. The low score is driven by the nature of 'zen' as a self-hosted personal notes application: the XSS payload is stored in a note the attacker (or an authenticated user) controls and executes largely in that same user's session, so the practical blast radius is small. No conflicting signals were detected between the vector and description - both point to an authenticated, interaction-dependent, limited-impact web XSS.

An authenticated user of a self-hosted zen instance saves a note whose content includes a crafted HTML/script payload; because NotesEditor.jsx renders note content via React's dangerouslySetInnerHTML without sanitization, the script executes when the note is rendered in a browser. A public proof-of-concept demonstrating this stored XSS exists (Notion write-up), so exploitation requires no novel research; realistic impact is limited to script execution in the note-viewer's browser session.