Obsidian Desktop CVE-2026-104078

Requires a vulnerable Obsidian Desktop build (per description, before 1.14.0) with its default Node-integration-enabled renderer, and the victim must open an attacker-controlled note in Live Preview mode and then actively click the rendered malicious anchor. The payload specifically depends on the bundled MathJax 3.2.2 Safe component's filterURL mishandling a TAB byte in the \href URL scheme to emit an empty protocol that evades the configured safeProtocols allowlist. Limiting factors that reduce real-world risk: the attacker cannot execute code without the victim's click (UI:A), the malicious note must first be delivered into or opened within the victim's vault (local vector, typically via a shared/synced/downloaded vault or social engineering), and users on patched versions or with Node integration disabled are not exploitable.

This is a genuine but conditionally-gated code-execution flaw rather than a drive-by remote compromise. The vendor-supplied CVSS 4.0 vector (AV:L/AC:L/AT:N/PR:N/UI:A) is internally consistent with the description: exploitation is unauthenticated (PR:N) but requires the victim to open an attacker-supplied note AND actively click a rendered link (UI:A), and the attack vector is Local (AV:L) because the malicious payload must already be present in the victim's vault/note rather than delivered over a live network protocol. Impact is high across confidentiality, integrity and availability (VC:H/VI:H/VA:H) because successful exploitation yields arbitrary OS command execution as the desktop user via Node integration - the practical ceiling of a non-privilege-escalation client compromise. No EPSS score, KEV listing, or public POC was provided in the intelligence, so there is no public exploit identified at time of analysis and no evidence of active exploitation; the 8.4 score is driven by impact severity, not by observed in-the-wild activity. Net: a real patch-worthy priority for Obsidian Desktop users who open shared/untrusted vaults, but the mandatory user-interaction and local-note prerequisites make mass, unattended exploitation unlikely. Note a version discrepancy in the source data - the description states 'before 1.14.0' while the only reference is the 1.14.4 changelog - which should be verified against the vendor before asserting a definitive fixed version.

An attacker shares or plants a Markdown note (e.g., in a synced/shared vault, a downloaded community vault, or a repo) containing a crafted MathJax \href whose URL scheme includes a TAB byte, causing filterURL to emit an empty protocol that bypasses safeProtocols and renders as a javascript: anchor. When the victim views the note in Live Preview and clicks the link, the javascript: URL executes in the Node-integration-enabled renderer and calls require('child_process') to run arbitrary OS commands as the desktop user. No public exploit code was identified at time of analysis, and success depends on the victim both opening the note and clicking the link.