How severe is CVE-2026-32815?

CVE-2026-32815 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-32815 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-32815?

CVE-2026-32815 affects B3log Siyuan. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-32815?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-32815 have an EU (EUVD) identifier?

Yes. CVE-2026-32815 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13336.

When was CVE-2026-32815 published?

CVE-2026-32815 was published on 2026-03-19 and last updated on 2026-06-17.

CVE-2026-32815

CVE-2026-32815 is a high-severity vulnerability in B3log Siyuan with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 5.3
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13336
Weakness: CWE-287
Affected product: B3log Siyuan
Published: 2026-03-19
Last modified: 2026-06-17

Description

SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the WebSocket endpoint (/ws) allows unauthenticated connections when specific URL parameters are provided (?app=siyuan&id=auth&type=auth). This bypass, intended for the login page to keep the kernel alive, allows any external client — including malicious websites via cross-origin WebSocket — to connect and receive all server push events in real-time. These events leak sensitive document metadata including document titles, notebook names, file paths, and all CRUD operations performed by authenticated users. Combined with the absence of Origin header validation, a malicious website can silently connect to a victim's local SiYuan instance and monitor their note-taking activity. This issue has been fixed in version 3.6.1.

Frequently asked questions

What is CVE-2026-32815?: SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the WebSocket endpoint (/ws) allows unauthenticated connections when specific URL parameters are provided (?app=siyuan&id=auth&type=auth). This bypass, intended for the login page to keep the kernel alive, allows any external client — including malicious websites via cross-origin WebSocket — to connect and receive all server push events in real-time. These events leak sensitive document metadata including document titles, notebook names, file paths, and all CRUD operations performed by authenticated users. Combined with the absence of Origin header validation, a malicious website can silently connect to a victim's local SiYuan instance and monitor their note-taking activity. This issue has been fixed in version 3.6.1.
How severe is CVE-2026-32815?: CVE-2026-32815 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-32815 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-32815?: CVE-2026-32815 affects B3log Siyuan. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-32815?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-32815 have an EU (EUVD) identifier?: Yes. CVE-2026-32815 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13336.
When was CVE-2026-32815 published?: CVE-2026-32815 was published on 2026-03-19 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*

More vulnerabilities in B3log Siyuan

CVE-2026-32938 — Critical (CVSS 9.9): SiYuan is a personal knowledge management system. In versions 3.6.0 and below, the /api/lute/html2BlockDOM on the…
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CVE-2026-33669 — Critical (CVSS 9.8): SiYuan is a personal knowledge management system. Prior to version 3.6.2, document IDs were retrieved via the…
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CVE-2024-55660 — Critical (CVSS 9.8): SiYuan is a personal knowledge management system. Prior to version 3.1.16, SiYuan's `/api/template/renderSprig`…
CVE-2024-53507 — Critical (CVSS 9.8): A SQL injection vulnerability was discovered in Siyuan 3.1.11 in /getHistoryItems.

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Other CWE-287 (Improper Authentication) vulnerabilities

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CVE-2026-42822 — Critical (CVSS 10.0): Improper authentication in Azure Local Disconnected Operations allows an unauthorized attacker to elevate privileges…
CVE-2026-20182 — Critical (CVSS 10.0): May 2026: This security advisory provides the details and fix information for a vulnerability that was discovered and…

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