SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-85584

SiYuan versions before v3.8.2 contain a denial of service vulnerability in the publish-service Basic Auth throttle that stores failed-attempt state using attacker-controlled usernames without enforcing capacity limits or eviction policies.

HIGH 8.7EPSS 0.33%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

SiYuan versions before v3.8.2 contain a denial of service vulnerability in the publish-service Basic Auth throttle that stores failed-attempt state using attacker-controlled usernames without enforcing capacity limits or eviction policies. Unauthenticated attackers can submit repeated authentication requests with unique invalid usernames to exhaust memory and increase synchronization overhead, degrading service availability.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
0.33% probability · 26th percentile
CISA KEV
Not listed
Weakness
CWE-770
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.