Security readout for executives and security teams
Plain-English summary
A flaw in SiYuan’s backlink and mention search can let an unauthenticated or low-privilege user manipulate the application database. Successful abuse could expose or alter information across notebooks. Public publishing surfaces create the clearest risk. SiYuan v3.7.4 contains the stated fix.
Executive priority
Prioritize emergency upgrading for internet-accessible publishing deployments. The vulnerability’s unauthenticated path and potential cross-notebook confidentiality and integrity impact justify immediate ownership and exposure review. Isolated instances still require prompt remediation because stored metadata can provide a second-order trigger.
Technical view
Backlink search builds a SQL MATCH statement by concatenating user keywords and stored block metadata. Escaping double quotes but not single quotes permits first- or second-order SQL injection. The statement-stacking-capable driver executes queries against the main read-write siyuan.db handle, potentially enabling arbitrary SQL and cross-notebook reads or writes.
Likely exposure
Treat SiYuan deployments older than v3.7.4 as requiring urgent review, especially when publishing is exposed. The bundle explicitly identifies versions through v3.7.2 as vulnerable and v3.7.4 as fixed; it does not clearly characterize v3.7.3. Anonymous and RoleReader access may reach the vulnerable publish-surface search.
Exploitation context
The source bundle reports no KEV listing and provides no evidence of active exploitation. Exploitation is described as network-reachable, low complexity, requiring neither privileges nor user interaction. Risk can arise directly from a supplied search keyword or later from maliciously stored document metadata.
Researcher notes
CWE-89 applies. The vulnerable inputs include client keywords and stored title, name, alias, or anchor metadata. The CVSS 3.1 score is 10.0 with scope change and high confidentiality and integrity impact. Version evidence is slightly inconsistent: the description says through v3.7.2, while the advisory framing says before v3.7.4.
Mitigation direction
- Upgrade SiYuan to v3.7.4 or later using vendor guidance.
- Restrict anonymous and RoleReader access to publishing surfaces until upgraded.
- Limit network access to affected instances where immediate upgrading is impossible.
- Preserve database backups and relevant logs before remediation or investigation.
Validation and detection
- Inventory SiYuan instances and record their exact versions.
- Confirm each remediated instance reports v3.7.4 or later.
- Identify whether publishing and backlink or mention search are externally reachable.
- Review logs for unusual backlink searches, SQL errors, or unexplained database activity.
- Check notebook data integrity against trusted backups where exposure existed.
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-89: Database access and collection lookup
Injection into data stores can inform collection, data access, and exfiltration detection reviews. 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 lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-72811 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
- 10 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A: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:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N3.95.8VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.9CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
Base CVSS 3.1 score
10CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/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-q2vg-7qgx-x5fc)CVE reference, VulnCheck · vendor-advisory
- VulnCheck Advisory: SiYuan before v3.7.4 SQL Injection via backlink searchCVE 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.
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.