CVE-2026-126264

SiYuan before 3.8.9 Sensitive File Disclosure via /api/file/getFile

SiYuan before 3.8.9 contains an information disclosure vulnerability that allows authenticated Reader users to retrieve credential-named widget files by bypassing the sensitive-path guard in getFile. Attackers can request paths like /data/widgets/<package>/credentials.json for publish-referenced widgets to obtain API keys, tokens, or other stored secrets.

CVSS 4.0 · 8.3 High EPSS n/a KEV · Not listed

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B3log

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Siyuan

CVE-2026-126265

SiYuan 2.1.0 before 3.8.9 CAPTCHA Bypass via Stale Login Cookie

SiYuan 2.1.0 before 3.8.9 contains a flaw where the loginAuth CAPTCHA challenge lives in a signed client-side cookie, allowing reuse of a solved challenge. Attackers can replay the original signed siyuan cookie with distinct wrong access codes to brute-force the code and gain an administrator session.

CVSS 4.0 · 9.1 Critical EPSS n/a KEV · Not listed

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B3log

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Siyuan

CVE-2026-126266

SiYuan from 3.6.0 before 3.8.9 Publish-Password Bypass via getDoc Regex Keywords

SiYuan from 3.6.0 before 3.8.9 contains an information disclosure vulnerability that allows unauthenticated publish visitors to bypass per-document passwords via regex search in getDoc. Attackers can send POST requests to /api/filetree/getDoc with queryMethod 3 and a broad regex to read protected body text returned in the unfiltered keywords field.

CVSS 4.0 · 8.7 High EPSS n/a KEV · Not listed

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B3log

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Siyuan

CVE-2026-126393

SiYuan before 3.8.10 SSRF via Skill-Install Download Redirect and DNS Rebinding

SiYuan before 3.8.10 contains a server-side request forgery vulnerability in the skill-install download path because fetchBytes performs only a parse-time hostname check instead of using ssrfSafeClient. Attackers can supply a skill URL via the MCP skill install action that redirects or DNS-rebinds to loopback addresses, reaching internal services and metadata endpoints.

CVSS 4.0 · 5.3 Medium EPSS n/a KEV · Not listed

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B3log

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Siyuan

CVE-2026-126776

SiYuan 3.7.0 before 3.8.10 Path Traversal File Write via MCP web_fetch

SiYuan 3.7.0 before 3.8.10 on Windows contains a path traversal vulnerability in kernel/util/webfetch.go that allows attackers to write files outside the import directory via backslash-encoded filenames. Attackers controlling a URL fetched by the MCP web_fetch or http_request tools can use %5C-encoded ..\ sequences to write chosen response bytes to directories above temp/import that are writable by the SiYuan user.

CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-123492

SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read

SiYuan before 3.8.9 contains a nil pointer dereference vulnerability in privateCacheMiddleware that allows authenticated attackers to crash the kernel by reading nonexistent MCP resources. Attackers with a valid API token can send a resources/read request in an initialized MCP session, causing a panic that terminates the kernel process and interrupts service.

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

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-116168

SiYuan before v3.8.7 Path Traversal Local File Read via MCP Asset Tool

SiYuan before 3.8.7 contains a path traversal vulnerability in the MCP asset tool because validateAssetUploadPaths relies on an incomplete sensitive-path blacklist that omits .env and other secret files. Authenticated attackers driving the MCP asset upload action can copy such local files into the workspace and read them back via /assets/ over HTTP.

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

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B3log

Products

Siyuan

CVE-2026-118680

SiYuan 3.8.7 through 3.8.8 Path Traversal via GLOBALROOT Alias

SiYuan 3.8.7 through 3.8.8 fails to normalize Windows GLOBALROOT device-namespace aliases, bypassing the IsSensitivePath denylist. Attackers can invoke importStdMd with a GLOBALROOT-prefixed path to copy the API token and TLS private key into the publicly served assets directory.

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

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-73608

SiYuan v3.7.4-alpha.2 Authorization Bypass via getAttributeViewSearchTarget

SiYuan's development branch (endpoint introduced by commit 9b8e8956f, not present in v3.7.3 or master, patched in v3.7.4-alpha.3) contains a missing-authorization vulnerability in the /api/av/getAttributeViewSearchTarget endpoint. The route is registered with CheckAuth only and performs no authorization checks (no CheckReadonly, no publish-access or encrypted-notebook gating). Given a database identifier taken from a published page and a keyword, an anonymous reader can query the endpoint to retrieve matching database row content, including rows that publish filters (FilterAttributeViewByPublishAccess) would otherwise withhold. No released stable version is affected.

CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-72791

SiYuan v3.7.4-alpha.1 Information Disclosure via getAttributeViewFieldViews

SiYuan v3.7.4-alpha.1 (a pre-release; the endpoint does not exist in stable v3.7.3 or earlier) contains an information disclosure vulnerability in the /api/av/getAttributeViewFieldViews endpoint. The route is registered with CheckAuth only and applies no publish-access filtering, so reader-role callers can retrieve the complete database view structure — every view's name, icon, layout type, and per-field Hidden flag — for any database whose avID is supplied, regardless of authorization. The issue was introduced by commit acfc02ee8 and fixed in v3.7.4-alpha.2.

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

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-116169

SiYuan 2.10.0 before 3.8.7 Stored XSS via KaTeX \href in Math Blocks

SiYuan from 2.10.0 before 3.8.7 contains a stored cross-site scripting vulnerability that allows users with edit permission to inject script by placing javascript: URLs in math block content rendered with KaTeX trust enabled. Attackers can store \href, \url, or \includegraphics payloads that mathRender assigns via innerHTML, executing script in the application origin when a reader clicks the rendered link.

CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-116170

SiYuan before v3.8.7 SQL Injection via History Search op and query

SiYuan before v3.8.7 contains an sql injection vulnerability that allows admin-token holders to read history.db by injecting unescaped op and type=3 query values. Attackers can send crafted UNION SELECT payloads to searchHistory or getHistoryItems endpoints to exfiltrate deleted document content, titles, and paths.

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

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-116166

SiYuan 3.6.0 before 3.8.7 Cleartext Transmission via Unenforced networkServeTLS Setting

SiYuan 3.6.0 before 3.8.7 accepts and persists the networkServeTLS setting but never enforces it, so the kernel port keeps serving full API access over plain HTTP alongside HTTPS. Network-adjacent attackers can sniff the cleartext login flow and session cookie, which lacks the Secure attribute while responses omit HSTS, to hijack kernel API sessions.

CVSS 4.0 · 7.6 High EPSS < 1% KEV · Not listed

Vendors

B3log

Products

Siyuan

CVE-2026-116171

SiYuan 3.5.4 before 3.8.7 Sensitive Path Bypass via Windows Extended-Length Prefix

SiYuan 3.5.4 before 3.8.7 on Windows contains a sensitive-path denylist bypass in IsSensitivePath because the Windows extended-length prefix (\\?\) survives filepath.Clean and matches no forbidden prefix. Authenticated API callers can prepend the prefix to localPath in /api/import/importStdMd to copy workspace conf files, including the API token and TLS private keys, into assets served to unauthenticated clients.

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

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B3log

Products

Siyuan

CVE-2026-100640

SiYuan before v3.8.4 Clipboard Data Disclosure via IPC

SiYuan before v3.8.4 contains an authorization omission in the siyuan-get IPC handler that allows remote-kernel renderers to access native clipboard formats by invoking clipboardReadMathML, clipboardReadOffice, and clipboardReadWPS commands with matching plaintext. Attackers controlling remote renderer content can obtain MathML formulas, Office bytes, and WPS bytes from local clipboard during user-mediated paste operations.

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

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-100635

SiYuan before v3.8.4 Authentication Bypass via Plaintext Session Cookie

SiYuan before v3.8.4 contains an authentication bypass vulnerability in the publish service where session cookies are issued without Secure or SameSite attributes over plaintext HTTP connections. An on-path attacker can observe a valid publish-visitor-session-id cookie from a Basic Auth exchange and replay it to access authenticated publish endpoints without knowing the account password.

CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-116167

SiYuan 2.9.0 before 3.8.7 XSS via check-auth to Parameter

SiYuan from 2.9.0 before 3.8.7 contains a cross-site scripting vulnerability in the unauthenticated /check-auth page that assigns the to parameter to window.location.href without scheme validation. Attackers can send a crafted link with a javascript: URI that executes after victim login, invoking kernel APIs to read or modify workspace content and settings.

CVSS 4.0 · 7.6 High EPSS < 1% KEV · Not listed

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-72798

SiYuan before v3.7.4 Information Disclosure via renderAttributeView

SiYuan versions before v3.7.4 fail to properly filter related-database content in renderAttributeView, allowing anonymous readers to access Relation and Rollup cell contents from hidden or password-protected databases. Attackers can request published databases that relate to restricted databases to retrieve sensitive content, or bypass row filtering entirely when the first column is a non-block type.

CVSS 4.0 · 9.2 Critical EPSS < 1% KEV · Not listed

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B3log Siyuan

Products

Siyuan Siyuan

CVE-2026-72805

SiYuan before v3.7.4 Information Disclosure via Block Endpoints

SiYuan versions before v3.7.4 fail to enforce publish-access checks on getBlockBreadcrumb, getRefText, and getBlockTreeInfos endpoints, allowing disclosure of protected document content and metadata. Anonymous readers or publish RoleReader accounts can retrieve document titles, ancestor block content snippets, reference text, and path metadata for publish-forbidden or password-protected documents by supplying block IDs.

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

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B3log Siyuan

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Siyuan Siyuan

CVE-2026-72797

SiYuan before v3.7.4 Information Disclosure via getEncryptedNotebookStatus

SiYuan versions before v3.7.4 contain an information disclosure vulnerability in the getEncryptedNotebookStatus endpoint that returns encrypted notebook identifiers, names, and lock states without publish-access filtering. Anonymous readers and publish-mode accounts can enumerate all encrypted notebooks and their current unlock status, revealing sensitive notebook names and decryption state in memory.

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

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B3log Siyuan

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Siyuan Siyuan