Security readout for executives and security teams
Plain-English summary
SiYuan versions before 3.7.4 can mistakenly expose encrypted notebook content through the publish API. If an encrypted notebook is unlocked, an anonymous remote reader may retrieve its decrypted documents without credentials or encryption keys. This creates a serious confidentiality risk for sensitive notes, business records, credentials, or customer information stored in affected notebooks.
Executive priority
Treat this as an immediate confidentiality incident-prevention priority. Rapidly identify externally reachable SiYuan deployments, upgrade versions before 3.7.4, and investigate possible anonymous access. Prioritize systems containing regulated, proprietary, credential, customer, or operational data.
Technical view
The publish-access logic does not correctly authorize requests involving encrypted notebooks. Affected systems treat unlocked encrypted notebooks as publicly accessible by default, allowing unauthenticated enumeration and retrieval of decrypted document content through the publish API. The issue is classified as missing authorization (CWE-862) and has CVSS 4.0 score 9.2, reflecting network-accessible, low-complexity confidentiality impact.
Likely exposure
Exposure is most likely where SiYuan before 3.7.4 serves unlocked encrypted notebooks through a reachable publish API. Internet-accessible deployments carry the greatest practical risk. The supplied evidence does not establish whether every affected installation enables or exposes publishing by default.
Exploitation context
The flaw requires no authentication, user interaction, or encryption key according to the supplied advisory data. CISA KEV status is false, and the provided sources do not report confirmed active exploitation. Absence from KEV does not prove that exploitation has not occurred.
Researcher notes
The affected boundary is stated as SiYuan before 3.7.4. The core weakness is authorization failure rather than cryptographic compromise: decrypted content becomes accessible after a notebook is unlocked. The supplied bundle gives no evidence of integrity or availability impact, public exploit tooling, observed attacks, or specific forensic indicators beyond relevant publish API access.
Mitigation direction
- Upgrade affected SiYuan installations to version 3.7.4 or later.
- Until upgraded, restrict external access to the publish API.
- Avoid leaving sensitive encrypted notebooks unlocked on affected systems.
- Review the vendor advisory for any additional configuration guidance.
Validation and detection
- Inventory SiYuan deployments and confirm their installed versions.
- Identify deployments exposing the publish API to untrusted networks.
- Determine whether encrypted notebooks were unlocked and publish-accessible.
- Review access logs for unexpected anonymous publish API requests.
- After upgrading, verify anonymous users cannot retrieve encrypted notebook content.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-862: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-72789 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.2 (4.0)
- Known Exploited
- No
- Published
Vector: 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
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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——VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N3.94VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.2CriticalVector: 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
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- GitHub Security Advisory (GHSA-v684-q882-jgmq)CVE reference, VulnCheck · vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 Authentication Bypass via Encrypted NotebooksCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Authorization
Missing Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.