CVE-2026-82649

SiYuan before 3.8.1 Local Privilege Escalation via Uncontrolled Search Path

HIGH
7
CVSS Score
Published: August 30, 2026 at 02:33 PM UTC
Updated: September 1, 2026 at 03:17 PM UTC
2 products affected across 2 vendorsSiyuanSiyuan

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Severity
HIGH7
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

SiYuan Windows installer before version 3.8.1 (affected versions >= 2.0.14) contains an uncontrolled search path element vulnerability in its NSIS installer, which invokes system executables such as TASKKILL by name rather than by absolute path. Because NSIS nsExec::Exec resolves these calls using a search path that includes the installer's own launch directory ahead of System32, an attacker who plants a malicious executable (e.g., a renamed TASKKILL.exe) in that directory can have it executed when the installer runs. These calls occur in electron-builder's preInit hook before the license page is displayed, and with an all-users (elevated) install the planted binary executes with an elevated token, resulting in local privilege escalation.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

2.0.14 ≤ v < 3.8.1
Affected range stops below 3.8.1, so it looks safe — our inference, not a vendor statement
2.0.14 ≤ v < 3.8.12.0.14
Vendor states this is fixed in 3.8.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCAutomatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7HIGHVulnCheck
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-427

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