VulnerabilityPublished 3 Aug 2026Updated 14 Aug 2026

CVE-2026-68587: siyuan · Missing Authorization

Affects siyuanSource CVE Database V5

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Not known to be exploited · CVSS 9.2 Critical : upgrade to 3.7.3 as a priority.

Data as of 1 Nov 2026, 11:03 UTC

CVSS 4.0 base score

9.2Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 25% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.7.3

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: High
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: None: There is no loss of integrity within the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: High: There is a total loss of confidentiality, resulting in all resources within the Subsequent System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade siyuan to 3.7.3.

Affected software

Product	Affected	Fixed in
siyuan-notesiyuan	Affected <3.7.3	Fixed in 3.7.3

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

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.

Summary

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.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 10 Aug 2026, 15:19 UTC

Technical details

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