Security readout for executives and security teams
Plain-English summary
SiYuan versions before 3.7.4 allow unlimited API-token guesses without CAPTCHA or account lockout. An attacker who discovers a weak token gains administrator access, including file operations and SQL queries. Internet-accessible deployments using short or predictable custom tokens face the greatest risk.
Executive priority
Treat remotely reachable, pre-3.7.4 deployments as an immediate remediation priority. Accelerate upgrades and token rotation because successful guessing grants administrator-level data access and modification capabilities. Prioritize exposed systems and those using weak custom tokens.
Technical view
The CheckAuth() middleware accepts Conf.Api.Token through Token/Bearer Authorization headers or the token query parameter. Neither authentication path uses NeedCaptcha or WrongAuthCount controls. This permits unauthenticated, remote, unthrottled guessing; a successful token authenticates with RoleAdministrator privileges.
Likely exposure
Exposure requires a SiYuan kernel version before 3.7.4 and reachable API authentication endpoints. Risk is highest when the service is remotely accessible and configured with a short, weak, reused, or exposed custom API token.
Exploitation context
The supplied sources describe a network-accessible attack requiring no authentication or user interaction. CVSS is 9.8. The CVE is not identified as KEV, and the source bundle provides no evidence of active exploitation or a public exploit.
Researcher notes
CWE-307 applies because authentication attempts are insufficiently restricted. Both header-based and query-parameter token paths reportedly bypass CAPTCHA and wrong-attempt counters. The provided evidence establishes impact and affected versions, but does not establish exploitation in the wild or detail the corrective implementation.
Mitigation direction
- Upgrade SiYuan to version 3.7.4 or later after reviewing the vendor advisory.
- Replace weak, short, reused, or potentially exposed API tokens with strong random values.
- Restrict API access to trusted networks or authenticated intermediaries where operationally feasible.
- Review current vendor guidance for any additional configuration changes or protective controls.
Validation and detection
- Inventory SiYuan deployments and confirm each running kernel version.
- Identify which API endpoints are reachable from untrusted networks.
- Review configuration securely for short, predictable, reused, or exposed API tokens.
- Examine access logs for repeated failed authorization attempts or token-bearing query requests.
- After upgrading, confirm the deployed kernel reports version 3.7.4 or later.
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-307: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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 lookupFile access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-73056 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
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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:U/C:H/I:H/A:H3.95.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.3CriticalVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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-m6w6-p7pc-fpg2)CVE reference, VulnCheck · vendor-advisory
- VulnCheck Advisory: SiYuan kernel before 3.7.4 Unthrottled Brute-Force via API TokenCVE 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 Restriction of Excessive Authentication Attempts
Improper Restriction of Excessive Authentication Attempts represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.