Which versions of SiYuan are affected by CVE-2026-72794?

Organizations running SiYuan note-taking software before version 3.7.4 face immediate risk of administrative account compromise through unauthenticated remote access when publish mode is enabled.. A patch is available.

Is there a public PoC exploit available for CVE-2026-72794?

Yes, a public proof-of-concept exploit is available for CVE-2026-72794. Prioritise patching immediately. EPSS: 0.2%.

How to fix or mitigate CVE-2026-72794?

Within 24 hours: identify all SiYuan instances running versions before 3.7.4 and determine which are running in publish mode; immediately restrict network access to these instances from untrusted sources. Within 7 days: disable publish mode if business requirements permit; if publish mode is essential, implement firewall or WAF rules to block the /api/system/getConf endpoint and restrict access to trusted networks; review session and administrative logs for signs of unauthorized access. Within 30 days: establish continuous monitoring of SiYuan security advisories for a patch release; upgrade all instances to version 3.7.4 or later immediately upon availability; conduct a comprehensive security audit of any administrative actions or data modifications that occurred during the vulnerability exposure period.

SiYuan CVE-2026-72794

Q: What is the CVSS score of CVE-2026-72794?

CVE-2026-72794 has a CVSS 4.0 base score of 9.2 (Critical). CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.2%.

EUVD-2026-57454 CRITICAL

Insufficiently Protected Credentials (CWE-522)

2026-08-12 VulnCheck

GHSA-34fj-mwm6-fjfg

GHSA-hg4j-w33m-p7g4

Information Disclosure Siyuan Siyuan Note

9.2

CVSS 4.0 · Vendor: VulnCheck

Severity by source

Vendor (VulnCheck) PRIMARY

9.2 CRITICAL

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

vuln.today AI

10.0 CRITICAL

Unauthenticated network endpoint (AV:N/AC:L/PR:N/UI:N) leaks a signing key in the auth component, so scope changes (S:C) and forged sessions yield high confidentiality and integrity impact; no availability effect.

3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

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

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Patch available

Aug 12, 2026 - 20:03 EUVD

Analysis Generated

Aug 12, 2026 - 19:56 vuln.today

CVE Published

Aug 12, 2026 - 19:07 cve.org

CRITICAL 9.2

DescriptionCVE.org

siyuan versions before v3.7.4 expose the session cookie signing key through the /api/system/getConf endpoint to unauthenticated users in publish mode. Attackers can retrieve the CookieKey value and forge valid session cookies to impersonate users or gain administrative access.

AnalysisAI

Credential disclosure in SiYuan note-taking software before v3.7.4 lets unauthenticated remote attackers read the session cookie signing key (CookieKey) from the /api/system/getConf endpoint when an instance runs in publish mode. With that key an attacker can mint valid signed session cookies, impersonate any user, and escalate to administrative control of the workspace. Reported by VulnCheck with a vendor security advisory (GHSA-34fj-mwm6-fjfg); no public exploit identified at time of analysis and the CVE is not listed in CISA KEV.

Technical ContextAI

SiYuan is a self-hosted, open-source personal knowledge-management and note-taking application with a built-in web server. Its 'publish mode' exposes a workspace as a read-oriented web service, and the /api/system/getConf endpoint returns the running configuration object. The root cause maps to CWE-522 (Insufficiently Protected Credentials): a secret used to sign/authenticate session cookies (CookieKey) is included in that configuration response and served to unauthenticated clients. Because the signing key is symmetric server-side material, disclosing it collapses the integrity guarantee of the entire session-cookie scheme - anyone holding the key can generate cookies the server will accept as genuine. The affected component is identified by CPE cpe:2.3:a:siyuan-note:siyuan:*:*:*:*:*:*:*:* across all versions prior to 3.7.4.

RemediationAI

Vendor-released patch: v3.7.4 - upgrade all SiYuan instances to v3.7.4 or later, which stops exposing the CookieKey through /api/system/getConf. Until you can upgrade, the highest-value compensating control is to take publish mode off the public internet: restrict access to the publish-mode listener behind a reverse proxy, VPN, or IP allowlist, or block/deny unauthenticated access to the /api/system/getConf path at the proxy (trade-off: a path block may break legitimate config reads by the client and is version-specific, so test it). Disabling publish mode entirely removes the exposure but also removes the publishing functionality, so it is only viable where that feature is not needed. Because the signing key was disclosed, after upgrading you should also rotate the CookieKey and invalidate existing sessions so any cookies forged before patching stop working. See the vendor advisory GHSA-34fj-mwm6-fjfg (https://github.com/siyuan-note/siyuan/security/advisories/GHSA-34fj-mwm6-fjfg) for authoritative guidance.