VulnerabilityPublished 12 Aug 2026Updated 14 Aug 2026

CVE-2026-72800: siyuan · Missing Authorization

Affects siyuanSource CVE Database V5

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Not known to be exploited · CVSS 6.9 Medium : upgrade to 3.7.4 when convenient.

Data as of 10 Nov 2026, 23:24 UTC

CVSS 4.0 base score

6.9Medium

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 3.7.4

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: Low
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Vulnerable System.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
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 12 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 11 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 3.7.4.

Affected software

Product	Affected	Fixed in
siyuan-notesiyuan	Affected <3.7.4	Fixed in 3.7.4

AI-suggested

Since the vulnerability affects versions before v3.7.4, upgrading to v3.7.4 or later is recommended once official fixes are available. Until then, restrict authenticated user access to trusted parties and monitor for unusual access patterns related to the affected endpoints.

Description

**CVE:** This vulnerability corresponds to [CVE-2026-72800](https://nvd.nist.gov/vuln/detail/CVE-2026-72800). ### Summary `POST /api/av/getAttributeViewKeysByID` returns a database's full column schema with no publish-access filtering, while its sibling `getAttributeViewKeys` applies the filter for reader sessions. Two further endpoints, `getBlockDefIDsByRefText` and `getBlockRelevantIDs` return workspace-wide block IDs with no publish scoping. All three are `CheckAuth`-only, so they are reachable by the publish `RoleReader` token and by the anonymous account when `Publish.Auth.Enable` is `false`. ### Details **(a) `getAttributeViewKeysByID`: ungated column-schema disclosure** The entire handler (`kernel/api/av.go`, router line 548): ```go ret.Data = model.GetAttributeViewKeysByID(avID, keyIDs...) // no publish gate ``` With an empty `keyIDs`, `GetAttributeViewKeysByID` calls `av.ParseAttributeView(avID)` and returns every column's `*av.Key`: | Field | Discloses | |---|---| | `Name`, `Desc` | column title and user-authored description | | `Options` | the full single/multi-select vocabulary and colours (e.g. status labels such as "Fired", "Confidential") | | `Template` | the column's Sprig template expression — logic and field references | | `Relation` | the target `avID`, allowing pivot to another database | | `Rollup`, `NumberFormat`, date config | further schema | **Guarded-sibling asymmetry, same file:** `getAttributeViewKeys` (router line 526) runs `FilterBlockAttributeViewKeysByPublishAccess(...)` when `IsReadOnlyRoleContext`. `getAttributeViewKeysByID` applies nothing. A reader who knows an `avID` — trivially harvested from the `data-av-id` attribute of any published document embedding a database obtains the schema of any database in the workspace, including those whose host documents are hidden, password-protected, or publish-forbidden. `Relation` targets allow walking to sibling databases. **(b) Two unscoped block-ID enumeration oracles** Both `CheckAuth`-only with no publish gate. Neither returns content of its own, but both yield valid block IDs that other endpoints turn into content: - `getBlockDefIDsByRefText` (router line 237) → `GetBlockDefIDsByRefText(anchor)` returns the block IDs, workspace-wide and including private documents, whose reference/anchor text equals a caller-supplied string: a ref-text → ID oracle. - `getBlockRelevantIDs` (router line 274) → `GetBlockRelevantIDsInBox(id, <notebook from request>)` returns parent/previous/next block IDs and traverses decrypted encrypted-notebook structure while the notebook is unlocked, a tree-walk oracle. Verified at `origin/master` (`eef105683`): all three handler bodies contain no publish-access, publish-ignore, or readonly-role check; all three routes are registered `CheckAuth` without `CheckAdminRole`. ### Proof of Concept Precondition: publish mode enabled (default port 6808); anonymous when `Publish.Auth.Enable` is `false`, otherwise any publish reader account. A database exists whose host document is publish-forbidden or password-protected. **(a) Column schema of any database:** ``` POST http://127.0.0.1:6808/api/av/getAttributeViewKeysByID {"avID":"<AV_ID>"} ``` Returns every column's key object names, descriptions, select vocabularies, template expressions, and `Relation` target `avID`s for a database whose host document the reader may not access. **Control:** the sibling `getAttributeViewKeys` with the same `avID` returns filtered results for the same reader session, confirming the boundary is enforced there and omitted here. **(b) ID oracles:** ``` POST http://127.0.0.1:6808/api/block/getBlockDefIDsByRefText {"anchor":"<known ref text>"} → block IDs workspace-wide, including blocks in private documents POST http://127.0.0.1:6808/api/block/getBlockRelevantIDs {"id":"<BLOCK_ID>","notebook":"<BOX_ID>"} → parent/previous/next block IDs; traverses encrypted-notebook structure when unlocked ``` ### Impact An anonymous reader (publish mode with auth disabled) or any publish `RoleReader` can read the complete column schema of any database in the workspace, including column descriptions, select-option vocabularies (which frequently encode sensitive category labels), template logic, and relation targets that permit pivoting to further databases regardless of whether the host document is hidden, password-protected, or excluded from publishing. The two enumeration endpoints additionally supply valid block IDs across the publish boundary, including from encrypted notebooks while unlocked. This removes the "attacker must already know a valid ID" precondition from other block-read endpoints, converting ID knowledge into content disclosure. Confidentiality-only. ### Note getAttributeViewKeysByID is a distinct handler from getAttributeView; although column definitions also appear within the latter's response payload, a fix applied to one handler does not remediate the other, and getAttributeViewKeysByID has its own filtered si

Impact

The vulnerability enables authenticated users with reader access to bypass publish-access restrictions and retrieve sensitive metadata and content identifiers from the database. This could lead to exposure of confidential or restricted information contained in hidden or password-protected documents. There is no indication of privilege escalation, remote code execution, or denial of service impacts.

Summary

CVE-2026-72800 describes an authorization bypass vulnerability in SiYuan note-taking software versions prior to v3.7.4. The getAttributeViewKeysByID endpoint lacks publish-access filtering, allowing authenticated readers to retrieve full database column schemas, including descriptions, select vocabularies, and template expressions. Additionally, the getBlockDefIDsByRefText and getBlockRelevantIDs endpoints enumerate workspace-wide block IDs without enforcing publish scoping, enabling discovery of valid block identifiers beyond intended publish boundaries. This results in unauthorized information disclosure of content from hidden or password-protected documents.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 12 Aug 2026, 19:43 UTC

Technical details

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