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CVE-2026-68587: Missing Authorization in siyuan-note siyuan

0
Critical
Published: 09/03/2026 (09/03/2026, 21:19:41 UTC)
Source: CVE Database V5
Vendor/Project: siyuan-note
Product: siyuan

Description

**CVE:** This vulnerability corresponds to [CVE-2026-68587](https://nvd.nist.gov/vuln/detail/CVE-2026-68587). ### Summary Three "heading transaction" endpoints `/api/block/getHeadingDeleteTransaction`, `/api/block/getHeadingLevelTransaction`, and `/api/block/getHeadingInsertTransaction` return the rendered block DOM of a heading and its subtree in the computed transaction payload, with no publish-access check. They are gated by `CheckAuth` only, so they are reachable by the publish `RoleReader` token, and by the anonymous account when `Publish.Auth.Enable` is `false`. Despite their write-implying names, these endpoints perform no mutation on this path, they compute a transaction object and return it, and that object contains `RenderNodeBlockDOM` output. As a result, an anonymous reader who supplies a heading block ID can read the full rendered content of a document that has been explicitly marked publish-disabled by an administrator, content that the reader-facing `/api/filetree/getDoc` path correctly refuses to return. ### Details **Route / auth tier.** All three routes are registered `CheckAuth`-only (no `CheckAdminRole`). `CheckAuth` admits `RoleReader`, and the publish proxy forwards port-6808 traffic with a Reader JWT (anonymous account when publish auth is disabled). Anonymous/reader reachable. **No publish-access filter.** `GetHeadingDeleteTransaction` / `GetHeadingLevelTransaction` / `GetHeadingInsertTransaction` load the heading's block tree and render its DOM into the returned transaction's operation data. None of the three invokes `IsReadOnlyRoleContext` / the publish-access filter that the reader-safe content path (`getDoc`) applies. The reader-facing content endpoints (`getDoc`, and the `CheckAdminRole`-gated `getBlockDOM`/`getBlockKramdown`) treat rendered block DOM as gated content; these three transaction endpoints return the same rendered DOM without that gate. **Write-implying name, read behavior.** On this code path the endpoints only *compute* the transaction (e.g. the `undoOperations` a delete would produce) and return it; nothing is deleted or modified. The returned operation data includes the rendered HTML of the heading subtree. This mismatch, mutation-shaped name, content-returning behavior is why the gap is easy to miss. ### Proof of Concept Reproduced on a local instance (SiYuan running locally, publish mode enabled on port 6808, publish Basic Auth disabled). `DOC` is a document containing a heading `HEADING` whose body contains the unique marker `UNIQUE_MARKER_99`, and `DOC` is marked publish-disabled by the administrator. **1. Confirm the document is publish-disabled (admin action, the boundary that should block reads):** ``` POST http://127.0.0.1:6806/api/filetree/setPublishAccess Authorization: Token <admin-token> {"id":"DOC","visible":false,"password":"","disable":true} ``` **2. Baseline: the reader-safe content path correctly blocks it (anonymous, port 6808):** ``` POST http://127.0.0.1:6808/api/filetree/getDoc {"id":"DOC"} ``` Returns the blocked/placeholder response, the publish filter is applied, no content. **3. Disclosure: the transaction endpoint returns the content (anonymous, port 6808):** ``` POST http://127.0.0.1:6808/api/block/getHeadingDeleteTransaction {"id":"HEADING"} ``` Returns HTTP 200; `data.undoOperations[].data` contains the rendered HTML of the heading subtree, including the hidden body text `UNIQUE_MARKER_99`. Nothing is deleted — the endpoint only computes the transaction. This is the full content of a publish-disabled document returned to an anonymous reader. **4. Sibling endpoints: same disclosure, same input:** ``` POST http://127.0.0.1:6808/api/block/getHeadingLevelTransaction {"id":"HEADING","level":2} POST http://127.0.0.1:6808/api/block/getHeadingInsertTransaction {"id":"HEADING"} ``` Both return the rendered DOM of the heading subtree in their operation data. ### Impact An anonymous reader (publish mode with auth disabled) or any publish `RoleReader` who supplies a heading block ID can read the full rendered content of a publish-disabled document, defeating a boundary the administrator explicitly configured. **Precondition:** the request requires the target heading's block ID. Block IDs are high-entropy and are not returned by this endpoint, so this endpoint alone does not permit untargeted enumeration of arbitrary documents. However, block/heading IDs for publish-disabled documents are obtainable from other `CheckAuth`-only endpoints that lack the publish-access filter (the publish-boundary handler set reported separately, e.g. `getHeadingChildrenIDs`). Chained with such an ID source, this yields end-to-end unauthenticated full-content disclosure of publish-disabled documents. Presented standalone, the attacker must already possess the heading ID. Impact is confidentiality-only: these endpoints return content but do not (on this path) modify data. No admin role, CSRF token, or write permission is required. Encrypted notebooks

CVSS v4.0

Score 9.2critical

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vuln. Confidentiality
High
Vuln. Integrity
None
Vuln. Availability
None
Subsq. Confidentiality
High
Subsq. Integrity
None
Subsq. Availability
None
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

Affected software

siyuan-note

siyuan

Affected versions
>=0 <3.7.3

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 08/10/2026, 15:19:34 UTC

Technical Analysis

CVE-2026-68587 describes an information disclosure vulnerability in SiYuan note-taking software affecting versions prior to v3.7.3. The vulnerability exists in the getHeadingDeleteTransaction, getHeadingLevelTransaction, and getHeadingInsertTransaction endpoints, which return rendered block DOM content without verifying publish-access permissions. As a result, unauthorized users, including anonymous readers or users with only RoleReader tokens, can supply a heading block ID to retrieve full rendered content of publish-disabled documents that should be inaccessible. This flaw leads to unauthorized information disclosure.

Potential Impact

Unauthorized users can access the full rendered content of documents that are intended to be restricted, potentially exposing sensitive or confidential information. The vulnerability does not require authentication or user interaction and affects the confidentiality of data handled by the affected endpoints. There are no known exploits in the wild at this time.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary workaround is currently documented. Users should monitor vendor communications for updates and consider restricting access to affected endpoints until a fix is available.

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Technical Details

Data Version
5.2
Assigner Short Name
VulnCheck
Date Reserved
2026-07-31T11:56:29.760Z
Cvss Version
4.0
State
PUBLISHED

Threat ID: 6a7098b1bf32cb7a34a82310

Added to database: 08/03/2026, 13:33:37 UTC

Last enriched: 08/10/2026, 15:19:34 UTC

Last updated: 09/17/2026, 22:01:37 UTC

Views: 46

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