CVE-2026-85174

SiYuan before v3.8.2 API Token Exposure via Log File

SiYuan before v3.8.2 logs API tokens from query parameters in plaintext to an accessible log file when full-text search requests exceed timing thresholds. Authenticated attackers can read the log file via the getFile endpoint to recover admin API tokens and gain permanent administrative access.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

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Siyuan Siyuan

CVE-2026-85582

SiYuan before v3.8.2 Unbounded Session Creation via Basic Auth

SiYuan versions before v3.8.2 contain an unbounded session creation vulnerability in the publish-service Basic Auth handler that allows authenticated attackers to exhaust memory. Attackers can repeatedly authenticate with valid credentials to create persistent session entries without expiry or capacity limits, causing indefinite process memory growth and denial of service.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-85585

SiYuan before v3.8.2 Unbounded Memory Consumption via ControlConcurrency

SiYuan before v3.8.2 contains an unbounded resource consumption vulnerability in the request-concurrency middleware that retains mutex entries for every unique request path without eviction. Unauthenticated attackers can send numerous unique request paths to permanently increase process memory and synchronization overhead, degrading availability.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-85580

SiYuan before v3.8.2 Path Guard Bypass via Case Mismatch

SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-85175

SiYuan before v3.8.2 TLS Private Key Disclosure via getFile

SiYuan versions <= 3.8.1 (fixed in v3.8.2) contain an incomplete blocklist in the IsForbiddenAbsPath() function (kernel/util/path_guard.go), which only blocks conf/conf.json by exact match and does not restrict the TLS private key (conf/key.pem) or CA private key (conf/ca.key) stored in the same conf/ directory. Because the getFile handler skips the blocklist for RoleAdministrator and all authenticated users receive RoleAdministrator in v3.8.1, any user (or any client on a default no-auth-code instance) can retrieve these private keys via POST /api/file/getFile. On deployments with TLS enabled, this allows decryption of captured HTTPS traffic (key.pem) and forging of certificates trusted by clients that imported SiYuan's CA (ca.key).

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-84803

SiYuan before v3.8.2 Stored XSS via incomplete asset blocklist

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in asset serving due to an incomplete extension blocklist that misses script-capable file types. Attackers can upload files with extensions like .xht, .ehtml, .xsl, .xbl, or .rdf that resolve to executable media types and execute JavaScript to steal API tokens and compromise workspaces.

CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82653

SiYuan before v3.8.1 Stored XSS via confirmDialog

SiYuan before v3.8.1 contains a stored cross-site scripting vulnerability in confirmDialog() where unescaped package names and notebook names are interpolated directly into innerHTML assignments. Attackers can submit malicious bazaar packages with HTML/script payloads in the name field that execute in users' browsers when uninstalling packages or unlocking encrypted notebooks.

CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82654

SiYuan before v3.8.1 Stored XSS via block name

SiYuan before v3.8.1 fails to properly escape block name, alias, and memo fields in hint, backlink, and breadcrumb rendering functions. Attackers can set a block's name to contain HTML/script tags that execute when another user views documents referencing or displaying that block.

CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82649

SiYuan before 3.8.1 Local Privilege Escalation via Uncontrolled Search Path

SiYuan Windows installer before version 3.8.1 (affected versions >= 2.0.14) contains an uncontrolled search path element vulnerability in its NSIS installer, which invokes system executables such as TASKKILL by name rather than by absolute path. Because NSIS nsExec::Exec resolves these calls using a search path that includes the installer's own launch directory ahead of System32, an attacker who plants a malicious executable (e.g., a renamed TASKKILL.exe) in that directory can have it executed when the installer runs. These calls occur in electron-builder's preInit hook before the license page is displayed, and with an all-users (elevated) install the planted binary executes with an elevated token, resulting in local privilege escalation.

CVSS 4.0 · 7 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82233

SiYuan before v3.8.1 Path Traversal via asset.upload

SiYuan before v3.8.1 contains a path traversal vulnerability in the asset.upload MCP tool that accepts arbitrary absolute file paths without workspace boundary validation. Attackers can induce the AI Agent to upload sensitive files such as SSH keys or credentials from outside the workspace into the asset directory through prompt injection.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82234

SiYuan before v3.8.1 SSRF via DNS-Rebinding TOCTOU

SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.

CVSS 4.0 · 8.4 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82650

SiYuan before v3.8.1 Path Traversal via /api/template/render

SiYuan 3.8.0 contains a path traversal / sensitive file exposure vulnerability in the RenderTemplate function (kernel/model/template.go), reachable via the POST /api/template/render endpoint (kernel/api/template.go). The endpoint restricts the supplied path only to the workspace directory (util.IsAbsPathInWorkspace) but, unlike the file API's refuseToAccess() blocklist, applies no sensitive-path exclusion. This allows an authenticated attacker to read sensitive workspace files, including conf/conf.json, which contains the API token and cookie signing key. The issue is fixed in v3.8.1.

CVSS 4.0 · 5.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82651

SiYuan before v3.8.1 Missing Authorization via /history and /repo/diff

SiYuan before v3.8.1 does not apply the IsForbiddenAbsPath guard (introduced in GHSA-c8r8-95hg-mp34) to the /history/*path and /repo/diff/*path endpoints in kernel/server/serve.go. These routes require admin authentication but construct file paths independently, so an authenticated administrator can retrieve historical snapshots of sensitive files that the guard is meant to block, including data/.siyuan/publishAccess.json (plaintext publish-mode passwords) and files under data/templates/.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-82652

SiYuan before v3.8.1 Information Disclosure via Publish Access

SiYuan before v3.8.1 fails to filter invisible-tier content from SQL embed blocks, attribute-view keys, and attribute-view backlinks in publish mode. Anonymous readers can enumerate invisible content through these three listing mechanisms despite admin configuration marking content unlisted.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-74802

SiYuan 3.7.3 Cross-Site WebSocket Hijacking via network proxy

SiYuan versions before 3.7.4 contain a cross-site WebSocket hijacking vulnerability in the admin-only /ws/network/proxy endpoint that explicitly disables origin validation by setting CheckOrigin to unconditionally return true. Attackers can craft malicious webpages that establish WebSocket connections to this endpoint and direct the SiYuan kernel process to proxy arbitrary network traffic to attacker-chosen targets, enabling authenticated network pivoting through the victim's machine.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-62204

SiYuan before v3.7.4 Plugin Overwrite via Bazaar Install

SiYuan versions before v3.7.4 fail to validate that packageName matches the downloaded package content in bazaar install endpoints. Attackers with same-origin access can overwrite existing trusted plugins by supplying mismatched packageName and repoURL parameters, achieving persistence across application restarts.

CVSS 4.0 · 5.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-59809

SiYuan before v3.8.0 Secret Exfiltration via http_request URL

SiYuan before v3.8.0 interpolates secret placeholders into the destination URL parameter of the http_request MCP tool, allowing attackers to exfiltrate stored secrets. An MCP client can craft a request with an attacker-controlled URL containing secret placeholders to send plaintext secret values to any public host without confirmation.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-74800

SiYuan before v3.7.4 Stored XSS via assets endpoint

SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full kernel API access when the workspace owner opens the asset link.

CVSS 4.0 · 9.4 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-73042

SiYuan before v3.7.4 Remote Code Execution via Menu Metadata

SiYuan before v3.7.4 fails to properly escape database menu metadata in HTML interpolation, allowing stored values to execute script when users open group, view, or field-edit menus. Attackers can inject markup through field descriptions or names that close containing elements and execute arbitrary code via event handlers, reaching Node built-ins due to Electron's insecure configuration.

CVSS 4.0 · 9.4 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-73047

siyuan before v3.7.4 Server-Side Template Injection via attribute-view

siyuan versions <= 3.7.3 (fixed in v3.7.4) contain a server-side template injection vulnerability in the attribute-view Template calculation feature (introduced in v3.7.0-beta.1). The feature's template engine uses Sprig's unmodified function map, which still exposes the env, expandenv, and getHostByName functions that were removed elsewhere for CVE-2024-55660. A local, unauthenticated attacker (the kernel binds to 127.0.0.1 by default with no per-UID access control) can inject a malicious Template calculation formula to read environment variables belonging to the account running siyuan — including from a separate, unprivileged OS account — and to perform DNS lookups from the server's network position.

CVSS 4.0 · 8.6 High EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan