CVE-2026-85583

SiYuan versions before v3.8.2 contain a path traversal flaw (CWE-59, improper link resolution before file access) in a reader-accessible file-read endpoint: when an authorized asset path under data/assets/ points to a symlink, the server follows the link beyond the workspace boundary. An attacker holding a reader-role account can request such a logical asset and receive the bytes of the target file outside the workspace, bypassing workspace restrictions. The impact is confidentiality-only — reading files reachable by the SiYuan service as the symlink target — with no write or availability impact, and triggering it requires valid reader credentials plus a symlink in the assets path. Deployments of SiYuan older than v3.8.2 that run the web service on a network reachable by other users and grant reader-role accounts are affected; purely local, single-user use is largely unaffected. There is no evidence of exploitation: the flaw is not in CISA KEV, EPSS is 0.5% (39th percentile), and no public PoC is known.

What to do: Upgrade to SiYuan v3.8.2 or later. As an interim measure, restrict reader-role access to trusted users and networks (e.g., VPN) and audit data/assets/ for symlinks pointing outside the workspace, removing or relocating any that expose sensitive files. Review access logs for asset-path requests issued by reader accounts.