VulnerabilityPublished 19 Mar 2026

CVE-2026-32815: siyuan · Improper Authentication

Affects siyuanSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 3.6.1 when convenient.

Data as of 1 Nov 2026, 08:20 UTC

CVSS 4.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 31% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.6.1

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: Passive
Vulnerable system confidentiality: Low
Vulnerable system integrity: None
Vulnerable system availability: None
Subsequent system confidentiality: None
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: Passive: Successful exploitation of this vulnerability requires limited interaction by the targeted user with the vulnerable system and the attacker’s payload. These interactions would be considered involuntary and do not require that the user actively subvert protections built into the vulnerable system.
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: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable 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 19 Mar 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 31 Oct 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 and siyuan-note/siyuan to 3.6.1.

Affected software

Product	Affected	Fixed in
siyuan-notesiyuan	Affected <3.6.1	Fixed in 3.6.1
GitHubsiyuan-note/siyuan`pkg:github/siyuan-note/siyuan`Other threats	Affected <3.6.1	Fixed in 3.6.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations and users should immediately upgrade SiYuan Note to version 3.6.1 or later, where this vulnerability is patched. Until upgrading, users should restrict access to the SiYuan Note WebSocket endpoint by implementing network-level controls such as firewall rules or local host restrictions to prevent external connections to the /ws endpoint. Browser security settings or extensions that block cross-origin WebSocket connections can reduce risk. Additionally, users should avoid visiting untrusted or malicious websites while SiYuan Note is running locally to mitigate cross-origin exploitation. Developers and administrators should verify that Origin header validation is enforced on WebSocket endpoints to prevent unauthorized cross-origin connections. Monitoring network traffic for unusual WebSocket connections and reviewing application logs for suspicious activity can help detect exploitation attempts. Finally, educating users about the risks of running vulnerable versions and visiting untrusted sites concurrently with SiYuan Note is important.

Description

CVE-2026-32815 is an improper authentication vulnerability in SiYuan Note versions 3.6.0 and below. The WebSocket endpoint (/ws) allows unauthenticated connections when specific URL parameters are used, enabling external clients, including malicious websites, to connect and receive real-time server push events. This leaks sensitive metadata such as document titles, notebook names, file paths, and CRUD operations performed by authenticated users. The lack of Origin header validation allows cross-origin WebSocket connections, enabling silent monitoring of a victim's local SiYuan instance. The vulnerability has been fixed in version 3.6.1. The CVSS 4.

Impact

The vulnerability allows attackers to bypass authentication and eavesdrop on sensitive user data in real-time, including document titles, notebook names, file paths, and all CRUD operations. This can lead to significant privacy violations, exposure of confidential information, and potential leakage of intellectual property or sensitive organizational data. Since the attack can be conducted silently via malicious websites exploiting cross-origin WebSocket connections, users may be unaware of the compromise. Organizations relying on SiYuan Note for sensitive knowledge management risk data leakage and espionage, especially if users access the application in environments where malicious websites can be visited. Although the vulnerability does not allow direct modification or deletion of data by attackers, the exposure of metadata and user activity can facilitate targeted social engineering, further attacks, or competitive intelligence gathering. The lack of authentication and Origin validation increases the attack surface, making exploitation feasible without user interaction or credentials.

CWE-287Improper Authentication (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Libraries or Frameworks
Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
Attack patterns
Fake the Source of Data (opens in a new tab)
Utilizing REST's Trust in the System Resource to Obtain Sensitive Data (opens in a new tab)
Session Hijacking (opens in a new tab)
Token Impersonation (opens in a new tab)
Upload a Web Shell to a Web Server (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Mar 2026, 19:33 UTC

WeaknessesCWE-287

Technical details

References

Community reviews

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