CVE-2026-73054Public exploitNetwork attack vectorHinoki check available

Unauthenticated event-stream disclosure via parser differential

Published Aug 15, 2026 · Updated Aug 15, 2026

Authentication bypass in SiYuan before 3.7.4 allows remote attackers to read live kernel event metadata through a crafted WebSocket URI. The keepalive exemption matches raw URI substrings, while session quarantine reads only the first duplicated query value, placing the connection in the broadcast pool. The flaw is reachable when an access auth code protects the kernel port and exposes identifiers, titles, paths, and operation logs, but not document bodies or write access.

CVSS severity8.7
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in SiYuan before 3.7.4 allows remote attackers to read live kernel event metadata through a crafted WebSocket URI. The keepalive exemption matches raw URI substrings, while session quarantine reads only the first duplicated query value, placing the connection in the broadcast pool. The flaw is reachable when an access auth code protects the kernel port and exposes identifiers, titles, paths, and operation logs, but not document bodies or write access.

The record

CVE
CVE-2026-73054
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
SiYuan Note
Product
SiYuan
Classifications
CWE-287, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.7.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SiYuan Note · SiYuanversion=0 <3.7.4

Published CVSS scores

8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
7.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-287Improper Authentication
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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