CVE-2026-100646

See a problem?
Please try reporting it to the source first.
Source
https://cve.org/CVERecord?id=CVE-2026-100646
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100646.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-100646
Aliases
  • GHSA-2w6q-wgc8-q743
Published
2026-09-26T13:23:17Z
Modified
2026-09-28T03:31:08Z
Severity
  • 8.6 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N CVSS Calculator
Summary
SiYuan before v3.8.4 Authentication Bypass via Missing Origin Header
Details

SiYuan is a self-hosted personal knowledge management system. In versions up to and including 3.8.3, the kernel's authentication guards (CheckAuth in kernel/model/session.go and IsSessionOriginAllowed in kernel/util/net.go) fail open when the HTTP Origin header is absent, on the incorrect assumption that any browser-initiated cross-site request carries an Origin. Because browsers omit Origin on cross-site top-level GET navigations and no-cors GET subresource loads — and the session cookie is SameSite=Lax — a single cross-site GET issued from any attacker-controlled web page is granted RoleAdministrator, both on default installations with no access-authorization code and on password-protected instances with a live session. Combined with content-type sniffing on the /api/network/proxy endpoint, which allows attacker-controlled HTML to be served under SiYuan's own origin, this permits an unauthenticated remote attacker to execute arbitrary script in the SiYuan origin (http://127.0.0.1:6806), invoke administrator APIs, and exfiltrate the persistent kernel API token. This issue is fixed in version 3.8.4.

Database specific 
{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-346"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100646.json"
}
References

Affected packages

Git / github.com/siyuan-note/siyuan

Affected ranges

Type
GIT
Repo
https://github.com/siyuan-note/siyuan
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
9f775e8a12daef8255556097396f9b2739078892
Database specific
Show details 
{
    "extracted_events":  [
        {
            "introduced":  "0"
        },
        {
            "fixed":  "3.8.4"
        }
    ],
    "source":  "AFFECTED_FIELD"
}

Affected versions

dev2.*
dev2.0.17-2
v0.*
v0.1.0
v0.1.1
v0.1.2
v0.1.3
v0.1.4
v0.1.5
v0.1.6
v0.1.7
v0.1.8
v0.1.9
v0.2.0
v0.2.1
v0.2.2
v0.2.3
v0.2.4
v0.2.5
v0.2.6
v0.2.7
v0.2.8
v0.2.9
v0.3.0
v0.3.1
v0.3.2
v0.3.3
v0.3.4
v0.3.5
v0.3.6
v0.3.7
v0.3.8
v0.3.9
v0.4.0
v0.4.1
v0.4.1-x2
v0.4.2
v0.4.3
v0.4.3-x1
v0.4.32
v0.4.4
v0.4.5
v0.4.6
v0.4.7
v0.4.8
v0.4.9
v0.4.91
v0.4.92
v0.4.93
v0.4.94
v0.5.0
v0.5.1
v0.5.2
v0.5.3
v0.5.4
v0.5.41
v0.5.42
v0.5.43
v0.5.44
v0.5.45
v0.5.46
v0.5.5
v0.5.6
v0.5.6-alpha1
v0.5.7
v0.5.8
v0.5.9
v0.6.0
v0.6.1
v0.6.2
v0.6.3
v0.6.4
v0.6.5
v0.6.6
v0.6.7
v0.6.8
v0.7.0
v0.7.1
v0.7.5
v0.7.8
v0.8.0
v0.8.5
v0.9.0
v0.9.2
v0.9.5
v0.9.6
v0.9.7
v0.9.8
v0.9.9
v1.*
v1.0.0
v1.0.1
v1.0.2
v1.0.3
v1.0.4
v1.0.5
v1.0.6
v1.0.7
v1.0.8
v1.0.9
v1.1.0
v1.1.1
v1.1.2
v1.1.3
v1.1.4
v1.1.5
v1.1.6
v1.1.7
v1.1.8
v1.1.81
v1.1.82
v1.1.83
v1.2.0
v1.2.0-beta1
v1.2.0-beta10
v1.2.0-beta11
v1.2.0-beta12
v1.2.0-beta13
v1.2.0-beta14
v1.2.0-beta15
v1.2.0-beta16
v1.2.0-beta2
v1.2.0-beta3
v1.2.0-beta4
v1.2.0-beta5
v1.2.0-beta6
v1.2.0-beta7
v1.2.0-beta8
v1.2.0-beta9
v1.2.0-rc1
v1.2.0-rc2
v1.2.0-rc3
v1.2.1
v1.2.2
v1.2.3
v1.2.31
v1.2.5
v1.2.6
v1.2.7
v1.2.8
v1.2.9
v1.3.0
v1.3.1
v1.3.2
v1.3.3
v1.3.4
v1.3.5
v1.3.6
v1.3.7
v1.3.8
v1.3.9
v1.4.0
v1.4.1
v1.4.2
v1.4.3
v1.4.4
v1.4.5
v1.4.6
v1.4.7
v1.4.8
v1.5.0
v1.5.1
v1.5.2
v1.5.3
v1.5.4
v1.5.5
v1.5.5-beta1
v1.5.5-beta2
v1.5.5-beta3
v1.5.6
v1.6.0
v1.6.1
v1.6.2
v1.6.3
v1.7.0
v1.7.1
v1.7.10
v1.7.11
v1.7.2
v1.7.3
v1.7.4
v1.7.5
v1.7.6
v1.7.7
v1.7.8
v1.7.9
v1.8.0
v1.8.1
v1.8.2
v1.8.4
v1.8.5
v1.8.6
v1.8.7
v1.8.8
v1.8.9
v1.9.0
v1.9.1
v1.9.2
v1.9.3
v1.9.4
v1.9.5
v1.9.6
v1.9.7
v1.9.8
v1.9.9
v2.*
v2.0.0
v2.0.0-beta1
v2.0.0-beta2
v2.0.1
v2.0.10
v2.0.11
v2.0.12
v2.0.13
v2.0.14
v2.0.15
v2.0.16
v2.0.17
v2.0.18
v2.0.19
v2.0.2
v2.0.20
v2.0.21
v2.0.21-dev1
v2.0.22
v2.0.23
v2.0.24
v2.0.25
v2.0.26
v2.0.26-dev1
v2.0.26-dev2
v2.0.27
v2.0.3
v2.0.4
v2.0.5
v2.0.6
v2.0.7
v2.0.8
v2.0.9
v2.1.0
v2.1.1
v2.1.10
v2.1.11
v2.1.12
v2.1.13
v2.1.14
v2.1.2
v2.1.3
v2.1.3-dev1
v2.1.4
v2.1.5
v2.1.6
v2.1.6-dev1
v2.1.7
v2.1.8
v2.1.8-dev1
v2.1.9
v2.10.0
v2.10.1
v2.10.1-dev1
v2.10.10
v2.10.11
v2.10.11-dev2
v2.10.12
v2.10.12-dev1
v2.10.13
v2.10.13-dev1
v2.10.13-dev5
v2.10.14
v2.10.14-dev1
v2.10.14-dev2
v2.10.15
v2.10.15-dev1
v2.10.16
v2.10.16-dev2
v2.10.2
v2.10.3
v2.10.3-dev1
v2.10.3-dev2
v2.10.3-dev3
v2.10.4
v2.10.4-dev1
v2.10.5
v2.10.5-dev1
v2.10.5-dev2
v2.10.6
v2.10.6-dev1
v2.10.6-dev2
v2.10.6-dev3
v2.10.6-dev4
v2.10.8
v2.10.8-dev1
v2.10.8-dev2
v2.10.8-dev3
v2.10.9
v2.10.9-dev3
v2.11.0
v2.11.0-dev2
v2.11.1
v2.11.1-dev1
v2.11.2
v2.11.2-dev1
v2.11.2-dev2
v2.11.2-dev3
v2.11.2-dev4
v2.11.2-dev5
v2.11.3
v2.11.3-dev1
v2.11.3-dev2
v2.11.4
v2.11.4-dev2
v2.11.4-dev4
v2.11.4-dev5
v2.11.4-dev6
v2.12.0
v2.12.0-dev1
v2.12.1
v2.12.1-dev3
v2.12.2
v2.12.3
v2.12.3-dev2
v2.12.4
v2.12.4-dev2
v2.12.5
v2.12.6
v2.12.7
v2.12.7-dev1
v2.12.7-dev2
v2.12.8
v2.12.8-dev2
v2.2.0
v2.2.1
v2.2.2
v2.2.3
v2.3.0
v2.3.1
v2.3.2
v2.3.3
v2.4.0
v2.4.1
v2.4.10
v2.4.11
v2.4.12
v2.4.12-dev2
v2.4.2
v2.4.3
v2.4.4
v2.4.5
v2.4.6
v2.4.7
v2.4.8
v2.4.9
v2.5.0
v2.5.0-dev1
v2.5.0-dev2
v2.5.1
v2.5.1-dev1
v2.5.1-dev2
v2.5.2
v2.5.2-dev2
v2.5.3
v2.5.3-dev2
v2.5.4
v2.5.4-dev1
v2.5.5
v2.5.5-dev1
v2.6.0
v2.6.0-dev1
v2.6.0-dev2
v2.6.0-dev3
v2.6.1
v2.6.1-dev3
v2.6.1-dev4
v2.6.1-dev5
v2.6.1-dev6
v2.6.1-dev7
v2.6.2
v2.6.3
v2.6.3-dev1
v2.6.3-dev2
v2.6.3-dev3
v2.6.3-dev4
v2.6.3-dev6
v2.7.0
v2.7.1
v2.7.1-dev1
v2.7.1-dev5
v2.7.10
v2.7.2
v2.7.2-dev1
v2.7.2-dev2
v2.7.2-dev3
v2.7.3
v2.7.3-dev3
v2.7.3-dev4
v2.7.4
v2.7.4-dev1
v2.7.5
v2.7.5-dev2
v2.7.6
v2.7.6-dev3
v2.7.6-dev4
v2.7.7
v2.7.7-dev1
v2.7.7-dev2
v2.7.7-dev3
v2.7.7-dev4
v2.7.8
v2.7.8-dev1
v2.7.9
v2.7.9-dev1
v2.7.9-dev2
v2.8.0
v2.8.0-dev1
v2.8.1-dev1
v2.8.1-dev2
v2.8.1-dev3
v2.8.10
v2.8.3
v2.8.3-dev1
v2.8.4
v2.8.4-dev2
v2.8.5
v2.8.5-dev1
v2.8.5-dev2
v2.8.5-dev3
v2.8.6
v2.8.6-dev1
v2.8.6-dev2
v2.8.6-dev4
v2.8.7
v2.8.7-dev2
v2.8.7-dev3
v2.8.7-dev5
v2.8.8
v2.8.8-dev1
v2.8.8-dev3
v2.8.9
v2.8.9-dev2
v2.8.9-dev3
v2.9.0
v2.9.0-dev1
v2.9.1
v2.9.1-dev1
v2.9.1-dev2
v2.9.2
v2.9.2-dev2
v2.9.2-dev3
v2.9.3
v2.9.3-dev1
v2.9.3-dev3
v2.9.4
v2.9.4-dev2
v2.9.5
v2.9.5-dev2
v2.9.6
v2.9.6-dev1
v2.9.7
v2.9.7-dev2
v2.9.7-dev3
v2.9.8
v2.9.8-dev1
v2.9.8-dev2
v2.9.9
v2.9.9-dev1
v3.*
v3.0.0
v3.0.0-dev1
v3.0.0-dev2
v3.0.1
v3.0.1-dev2
v3.0.10
v3.0.10-dev1
v3.0.10-dev3
v3.0.11
v3.0.12
v3.0.12-dev1
v3.0.12-dev4
v3.0.12-dev5
v3.0.13-dev3
v3.0.13-dev4
v3.0.14
v3.0.15
v3.0.15-dev1
v3.0.15-dev2
v3.0.16
v3.0.16-dev3
v3.0.17
v3.0.17-dev1
v3.0.17-dev2
v3.0.2
v3.0.2-dev2
v3.0.3
v3.0.3-dev4
v3.0.3-dev5
v3.0.4
v3.0.4-dev2
v3.0.5
v3.0.5-dev3
v3.0.5-dev4
v3.0.5-dev5
v3.0.6
v3.0.6-dev2
v3.0.6-dev3
v3.0.7
v3.0.7-dev1
v3.0.8
v3.0.8-dev1
v3.0.8-dev2
v3.0.9
v3.1.0
v3.1.0-dev10
v3.1.0-dev11
v3.1.0-dev12
v3.1.0-dev2
v3.1.0-dev3
v3.1.0-dev8
v3.1.0-dev9
v3.1.1-dev1
v3.1.1-dev2
v3.1.10
v3.1.10-dev1
v3.1.10-dev6
v3.1.11
v3.1.11-dev2
v3.1.11-dev5
v3.1.11-dev9
v3.1.12
v3.1.12-dev2
v3.1.12-dev3
v3.1.12-dev4
v3.1.13
v3.1.14
v3.1.14-dev2
v3.1.15
v3.1.15-dev1
v3.1.15-dev3
v3.1.16
v3.1.17
v3.1.18
v3.1.19
v3.1.19-dev3
v3.1.2
v3.1.2-dev2
v3.1.2-dev3
v3.1.2-dev4
v3.1.20
v3.1.20-dev3
v3.1.20-dev4
v3.1.21
v3.1.21-dev1
v3.1.21-dev3
v3.1.21-dev4
v3.1.22
v3.1.22-dev1
v3.1.22-dev2
v3.1.23
v3.1.24
v3.1.25
v3.1.25-dev3
v3.1.25-dev4
v3.1.25-dev6
v3.1.26
v3.1.26-dev1
v3.1.26-dev2
v3.1.26-dev3
v3.1.27
v3.1.27-dev1
v3.1.27-dev2
v3.1.27-dev4
v3.1.28
v3.1.28-dev2
v3.1.28-dev3
v3.1.29
v3.1.29-dev3
v3.1.3
v3.1.3-dev1
v3.1.3-dev2
v3.1.30
v3.1.30-dev1
v3.1.31
v3.1.32
v3.1.32-dev2
v3.1.4
v3.1.4-dev2
v3.1.4-dev3
v3.1.4-dev5
v3.1.5
v3.1.6
v3.1.6-dev1
v3.1.6-dev2
v3.1.7
v3.1.7-dev3
v3.1.7-dev4
v3.1.7-dev5
v3.1.7-dev7
v3.1.7-dev8
v3.1.8
v3.1.8-dev2
v3.1.8-dev3
v3.1.9
v3.1.9-dev1
v3.1.9-dev10
v3.1.9-dev2
v3.1.9-dev3
v3.1.9-dev4
v3.1.9-dev6
v3.1.9-dev7
v3.1.9-dev9
v3.2.0-dev1
v3.2.0-dev10
v3.2.0-dev2
v3.2.0-dev3
v3.2.0-dev4
v3.2.0-dev6
v3.2.0-dev8
v3.2.0-dev9
v3.2.1
v3.2.1-dev2
v3.2.1-dev3
v3.2.1-dev4
v3.2.1-dev5
v3.2.1-dev6
v3.3.0
v3.3.0-dev3
v3.3.0-dev4
v3.3.1
v3.3.2
v3.3.2-dev1
v3.3.2-dev2
v3.3.3
v3.3.3-dev1
v3.3.3-dev2
v3.3.3-dev3
v3.3.3-dev4
v3.3.3-dev5
v3.3.4
v3.3.4-dev1
v3.3.4-dev2
v3.3.5
v3.3.6
v3.3.6-dev1
v3.3.6-dev2
v3.4.0
v3.4.0-dev1
v3.4.0-dev2
v3.4.0-dev3
v3.4.0-dev4
v3.4.0-dev5
v3.4.1
v3.4.1-dev1
v3.4.2
v3.4.2-dev1
v3.5.0
v3.5.0-dev1
v3.5.0-dev2
v3.5.1
v3.5.1-dev1
v3.5.1-dev2
v3.5.10
v3.5.2
v3.5.2-dev1
v3.5.2-dev2
v3.5.3
v3.5.3-dev2
v3.5.3-dev3
v3.5.3-dev4
v3.5.3-dev5
v3.5.4
v3.5.4-dev1
v3.5.4-dev2
v3.5.4-dev3
v3.5.4-dev5
v3.5.5
v3.5.7
v3.5.8
v3.5.8-dev2
v3.5.9
v3.6.0
v3.6.1
v3.6.2
v3.6.3
v3.6.4
v3.6.4-dev2
v3.6.5
v3.6.5-dev2
v3.7.0-dev12
v3.7.0-dev2
v3.7.0-dev5
v3.7.0-dev8
v3.7.0-rc.1
v3.7.0-rc.2
v3.7.3
v3.7.3-beta.1
v3.7.3-beta.2
v3.7.4-alpha.2
v3.7.4-alpha.4
v3.8.0
v3.8.0-alpha.2
v3.8.0-alpha.3
v3.8.0-alpha.4
v3.8.0-beta.2
v3.8.1
v3.8.1-beta.1
v3.8.1-beta.4
v3.8.1-beta.5
v3.8.1-beta.6
v3.8.2-alpha.1
v3.8.2-alpha.3
v3.8.2-alpha.4
v3.8.2-alpha.5
v3.8.2-alpha.6
v3.8.3
v3.8.3-alpha.1
v3.8.3-alpha.2
v3.8.3-alpha.3
v3.8.3-beta.1
v3.8.4-beta.1
v3.8.4-beta.2
v3.8.4-beta.3
v3.8.4-beta.4
v3.8.4-beta.5

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100646.json"