SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-116166

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.

HIGH 7.6EPSS 0.11%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 4.0
7.6 HIGHCVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/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/M
EPSS
0.11% probability · 2th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-319
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%26 October 2026: 0.11%26 October 202626 October 2026

EPSS 0.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.