High · CVSS 8.7CVE-2026-116171

SiYuan 3.5.4 before 3.8.7 Sensitive Path Bypass via Windows Extended-Length PrefixCVE-2026-116171

Answer in brief

CVE-2026-116171 records a High severity (CVSS 8.7) vulnerability in SiYuan 3.5.4 before 3.8.7 Sensitive Path Bypass via Windows Extended-Length Prefix. The current sources do not mark it as known exploited. The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 25, 2026Updated Oct 25, 2026Source checked Oct 25, 2026First seen by HOL Oct 25, 2026Material review Oct 25, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.7
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps siyuan-note/siyuan (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
siyuan-note/siyuangeneric	>=3.5.4 <3.8.7	3.8.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for siyuan-note/siyuan.
Review the reported fix. Update siyuan-note/siyuan to 3.8.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 25, 2026

Sources and claim methodology

Upstream source description

SiYuan 3.5.4 before 3.8.7 on Windows contains a sensitive-path denylist bypass in IsSensitivePath because the Windows extended-length prefix (\\?\) survives filepath.Clean and matches no forbidden prefix. Authenticated API callers can prepend the prefix to localPath in /api/import/importStdMd to copy workspace conf files, including the API token and TLS private keys, into assets served to unauthenticated clients.

Quoted source text, attributed separately from HOL analysis.