What is CVE-2026-72809?

CVE-2026-72809 is a high-severity vulnerability in Siyuan-note Siyuan, classified under Authentication Bypass by Spoofing. CVSS score: 8.0/10. Published 2026-08-12.

How severe is CVE-2026-72809?

High severity. CVSS v3 base score is 8.0 out of 10.

Vulnerability in Siyuan-note Siyuan

CVE-2026-72809

SiYuan versions <= v3.7.2 (patched in v3.7.4) contain an authentication bypass vulnerability in the kernel's CheckAuth function, which grants the administrator role (RoleAdministrator) to any request whose RemoteAddr is loopback (127.0.0.1…

CVSS v3 metric

CVSS v3 base score 8.0 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H.

Affected products

Siyuan-note Siyuan — versions 0, 3.7.4

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-72809?: CVE-2026-72809 is a high-severity vulnerability in Siyuan-note Siyuan, classified under Authentication Bypass by Spoofing. CVSS score: 8.0/10. Published 2026-08-12.
How severe is CVE-2026-72809?: High severity. CVSS v3 base score is 8.0 out of 10.