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CVE-2026-85583

HIGH 7.1

Published 2026-09-04 · Last modified 2026-09-04

SiYuan versions before v3.8.2 contain a path traversal vulnerability in the reader-accessible file-read endpoint that follows symlinks when opening authorized asset paths. Attackers with reader role can request a logical asset under data/assets/ that is a symlink to a file outside the workspace and receive the target file bytes, bypassing workspace boundary restrictions.

ELEVATED IMPACT

Severe if exploited (CVSS 7.1), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

EPSS not yet scored

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.1CVSS 4.0 · HIGH

  • ConfidentialityHigh
  • IntegrityNone
  • AvailabilityNone

What an attacker needs

  • Access: Reachable over the network — no local access needed
  • Privileges: Requires a low-privilege account
  • User interaction: No user interaction needed
  • Complexity: No special conditions — reliably repeatable
  • Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-85583/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-85583/poc.json

Affected

Vendors Siyuan Note

Products Siyuan

Weakness (CWE)

  • CWE-59: Improper Link Resolution Before File Access ('Link Following')

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

All CVSS metrics

  • HIGH 7.1 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
  • MEDIUM 6.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
  • HIGH 7.1 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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
  • MEDIUM 6.5 v3.1 · NVD Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Sources: NVD · CVE.org · EPSS