CVE-2026-73054

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

Summary

Two checks on the same WebSocket request URI parse it differently. The authentication exemption for keepalive sessions matches raw substrings, while the quarantine introduced to contain those sessions reads a parsed query parameter. Because Go's url.Values.Get returns only the first value for a repeated key, a single URI can satisfy the exemption and still resolve to a non-auth session identity.

The result is that an unauthenticated remote caller connects to the kernel WebSocket with a valid access auth code configured, is placed in the general broadcast pool rather than the quarantined pool, and receives the live event stream.

Details

The exemption matches substrings. kernel/server/serve.go:1222 on the development branch, :1074 on master:

authOk = strings.Contains(s.Request.RequestURI, "/ws?app=siyuan") &&
         strings.Contains(s.Request.RequestURI, "&id=auth&type=auth")

Neither operand is parsed. Any URI containing both literals is exempted, regardless of what the query actually resolves to.

The quarantine parses. Commit 1e370e373 added the containment for exempted sessions at kernel/util/websocket.go:171:

id = session.Request.URL.Query().Get("id")
return "auth" == id

url.Values.Get returns the first value for a repeated key.

The differential. For the URI:

/ws?app=siyuan&id=main&type=main&id=auth&type=auth

• It contains /ws?app=siyuan and &id=auth&type=auth, so authOk is true. No cookie, no JWT and no access auth code are required.
• Query().Get("id") returns main, so IsAuthSession is false. AddPushChan files the session in sessions, the broadcast pool, rather than in authSessions.
• Query().Get("type") returns main, so the session matches BroadcastByType("main", ...).
• Without a valid X-Auth-Token the publish flag is never set, so isPublishSession() does not exclude it either.

Every guard that should have caught the session keys off a different parse than the one that admitted it.

No origin validation. CheckOrigin does not appear on the /ws path, so the cross-origin vector described in the parent advisory also remains available.

Distinction from the existing broadcast-pool advisory. GHSA-mw8r-mw84-88v2 concerns the publish port, where an anonymous session is expected to connect and the defect is that broadcast content is not gated for it afterwards. This report concerns the kernel port with an access auth code configured, where the session should never be admitted in the first place. The leaked data overlaps because both end in the same broadcast pool, but the mechanisms and the affected deployments are different, and gating publish sessions does not close this path.

Proof of Concept

Kernel port, --accessAuthCode set. Three WebSocket connections, none carrying credentials of any kind.

| Socket | Query | Result | |---|---|---| | A, baseline | ?app=siyuan&id=main&type=main | Rejected, closed 1002, 0 frames | | B, control | ?app=siyuan&id=auth&type=auth | Connects, 0 frames | | C, attack | ?app=siyuan&id=main&type=main&id=auth&type=auth | Connects, 19 to 30 frames across two runs |

Socket A establishes that the access auth code is enforced. Socket B establishes that the existing quarantine works exactly as intended, admitting the keepalive session but delivering nothing to it. Socket C differs from B only in the duplicated parameters, and receives the event stream.

Frames observed on socket C included savedoc ("action":"create","data":{"Root":{"ID": ...), transactions ("action":"updateAttrs" carrying document titles), filetreeSortChanged (the notebook's complete ordered childIDs), create (a notebook object including its name), and backgroundtask.

A canary string placed inside a document body did not appear in any frame, on a full-text search of all captured frames.

Impact

An unauthenticated remote caller obtains the kernel's live event stream on a deployment…

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-c8w8-3pqp-wr83. This link is maintained to preserve external references.

Original Description

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

Summary

Two checks on the same WebSocket request URI parse it differently. The authentication exemption for keepalive sessions matches raw substrings, while the quarantine introduced to contain those sessions reads a parsed query parameter. Because Go's url.Values.Get returns only the first value for a repeated key, a single URI can satisfy the exemption and still resolve to a non-auth session identity.

The result is that an unauthenticated remote caller connects to the kernel WebSocket with a valid access auth code configured, is placed in the general broadcast pool rather than the quarantined pool, and receives the live event stream.

Details

The exemption matches substrings. kernel/server/serve.go:1222 on the development branch, :1074 on master:

authOk = strings.Contains(s.Request.RequestURI, "/ws?app=siyuan") &&
         strings.Contains(s.Request.RequestURI, "&id=auth&type=auth")

Neither operand is parsed. Any URI containing both literals is exempted, regardless of what the query actually resolves to.

The quarantine parses. Commit 1e370e373 added the containment for exempted sessions at kernel/util/websocket.go:171:

id = session.Request.URL.Query().Get("id")
return "auth" == id

url.Values.Get returns the first value for a repeated key.

The differential. For the URI:

/ws?app=siyuan&id=main&type=main&id=auth&type=auth

• It contains /ws?app=siyuan and &id=auth&type=auth, so authOk is true. No cookie, no JWT and no access auth code are required.
• Query().Get("id") returns main, so IsAuthSession is false. AddPushChan files the session in sessions, the broadcast pool, rather than in authSessions.
• Query().Get("type") returns main, so the session matches BroadcastByType("main", ...).
• Without a valid X-Auth-Token the publish flag is never set, so isPublishSession() does not exclude it either.

Every guard that should have caught the session keys off a different parse than the one that admitted it.

No origin validation. CheckOrigin does not appear on the /ws path, so the cross-origin vector described in the parent advisory also remains available.

Distinction from the existing broadcast-pool advisory. GHSA-mw8r-mw84-88v2 concerns the publish port, where an anonymous session is expected to connect and the defect is that broadcast content is not gated for it afterwards. This report concerns the kernel port with an access auth code configured, where the session should never be admitted in the first place. The leaked data overlaps because both end in the same broadcast pool, but the mechanisms and the affected deployments are different, and gating publish sessions does not close this path.

Proof of Concept

Kernel port, --accessAuthCode set. Three WebSocket connections, none carrying credentials of any kind.

| Socket | Query | Result | |---|---|---| | A, baseline | ?app=siyuan&id=main&type=main | Rejected, closed 1002, 0 frames | | B, control | ?app=siyuan&id=auth&type=auth | Connects, 0 frames | | C, attack | ?app=siyuan&id=main&type=main&id=auth&type=auth | Connects, 19 to 30 frames across two runs |

Socket A establishes that the access auth code is enforced. Socket B establishes that the existing quarantine works exactly as intended, admitting the keepalive session but delivering nothing to it. Socket C differs from B only in the duplicated parameters, and receives the event stream.

Frames observed on socket C included savedoc ("action":"create","data":{"Root":{"ID": ...), transactions ("action":"updateAttrs" carrying document titles), filetreeSortChanged (the notebook's complete ordered childIDs), create (a notebook object including its name), and backgroundtask.

A canary string placed inside a document body did not appear in any frame, on a full-text search of all captured frames.

Impact

An unauthenticated remote caller obtains the kernel's live event stream on a deployment…

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-c8w8-3pqp-wr83. This link is maintained to preserve external references.

Original Description

SiYuan versions before v3.7.4 contain an authentication bypass vulnerability in the WebSocket endpoint caused by differential parsing of query parameters between authentication exemption and session quarantine checks. Unauthenticated attackers can craft a malicious WebSocket URI with duplicated query parameters to bypass access auth code validation and receive the live kernel event stream including document identifiers, titles, and operation logs.

SiYuan: A parser differential between the WebSocket keepalive exemption and the session quarantine allows unauthenticated access to the broadcast event stream in github.com/siyuan-note/siyuan/kernel