Vulnerability in Siyuan-Note Siyuan
CVE-2026-116166
SiYuan 3.6.0 before 3.8.7 accepts and persists the networkServeTLS setting but never enforces it, so the kernel port keeps serving full API access over plain HTTP alongside HTTPS. Network-adjacent attackers can sniff the cleartext login flow and session cookie, which lacks the Secure attribute while responses omit HSTS, to hijack kernel API sessions.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-hpj5-f7cj-vvwr (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-3.6.0-before-3.8.7-cleartext-transmission-v… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-116166?
- CVE-2026-116166 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Cleartext Transmission of Sensitive Information. CVSS score: 6.8/10. Published 2026-10-25.
- How severe is CVE-2026-116166?
- Medium severity. CVSS v3 base score is 6.8 out of 10.