SiYuan CVE-2026-86192

Exploitation requires the attacker to hold a valid Publish reader account on a SiYuan instance running in multi-user or server mode with the publish and sharing feature enabled. The attacker needs network access to the getAttributeViewKeys API endpoint and must be able to supply or enumerate attribute-view row identifiers. Default single-user desktop deployments of SiYuan are not exposed because no external users exist. Exploitation is bounded to authenticated low-privilege users (PR:L per CVSS 4.0); anonymous or unauthenticated access is not sufficient. No user interaction from an administrator or document owner is required once the attacker has a Publish reader credential.

The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N) reflects a straightforward network-reachable, low-complexity authorization bypass with high confidentiality impact and no integrity or availability consequences, yielding a 7.1 score. This is well-calibrated: the impact ceiling is bounded by what users store in attribute-view fields, which in an enterprise or team context could include credentials, financial records, or sensitive planning data. No KEV listing confirms active exploitation, no EPSS figure was supplied, and no public POC has been identified, all of which temper urgency. However, the low exploitation bar - only a Publish reader account is needed - means that even a mid-sized municipal IT team in inowroclaw running a shared SiYuan server with guest sharing enabled should treat this as urgent if sensitive data is stored in attribute views. The primary risk limiter is deployment mode: SiYuan is designed as a local-first tool and most users run it as a single-user desktop application, substantially reducing the attack surface. Multi-user server deployments with the publish/sharing feature enabled represent the realistic threat population. The 'Authentication Bypass' tag in the input metadata is inaccurate - this is a post-authentication authorization bypass, not a mechanism to circumvent login.

An attacker who has been granted Publish reader access to a shared SiYuan server - for example, to view published notes - enumerates or guesses row identifiers in the attribute-view database. They call the getAttributeViewKeys endpoint directly with those identifiers and receive back hidden KeyValues from rows tied to private, inaccessible documents, extracting structured data such as stored credentials, API keys, or internal planning fields that the document owner believed were protected.