CVE-2026-100635

Published: Sep 26, 2026Modified: Oct 8, 2026Deferred

8.2

Vector

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

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:XShow less

Source: disclosure@vulncheck.com (Secondary)

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.

Related CWEs

CWE-319

Cleartext Transmission of Sensitive Information

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

References (5)

https://github.com/siyuan-note/siyuan/commit/79d47867b106467c951475a9193455b48d1f3682

Source: disclosure@vulncheck.com

https://github.com/siyuan-note/siyuan/commit/ff4d215f78a8d6e6db6052be18b5f9f4db9c7d68

Source: disclosure@vulncheck.com

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-7j37-4gq6-wm7m

Source: disclosure@vulncheck.com

https://www.vulncheck.com/advisories/siyuan-before-3.8.4-authentication-bypass-via-plaintext-session-cookie

Source: disclosure@vulncheck.com

https://github.com/siyuan-note/siyuan/security/advisories/GHSA-7j37-4gq6-wm7m

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0

Timeline

No history available yet.