Description
SiYuan before v3.8.4 contains an authentication bypass vulnerability in the publish service where session cookies are issued without Secure or SameSite attributes over plaintext HTTP connections. An on-path attacker can observe a valid publish-visitor-session-id cookie from a Basic Auth exchange and replay it to access authenticated publish endpoints without knowing the account password.
References5
- github.com/siyuan-note/siyuan/commit/79d47867b106467c951475a919…
- github.com/siyuan-note/siyuan/commit/ff4d215f78a8d6e6db6052be18…
- github.com/siyuan-note/siyuan/security/advisories/GHSA-7j37-4gq…
- www.vulncheck.com/advisories/siyuan-before-3.8.4-authentication…
- github.com/siyuan-note/siyuan/security/advisories/GHSA-7j37-4gq…
Metrics
- CVSS 3.1
-
5.9
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 4.0
-
8.2
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 26 · as of 9 November 2026
- CWE
- CWE-319
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.