Vulnpedia
← All CVEs

CVE-2026-73042

CRITICAL 9.4

Published 2026-08-15 · Last modified 2026-08-17

SiYuan before v3.7.4 fails to properly escape database menu metadata in HTML interpolation, allowing stored values to execute script when users open group, view, or field-edit menus. Attackers can inject markup through field descriptions or names that close containing elements and execute arbitrary code via event handlers, reaching Node built-ins due to Electron's insecure configuration.

ELEVATED IMPACT

Severe if exploited (CVSS 9.4), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.3%chance of exploitation in 30 days · 23rd percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

9.4CVSS 4.0 · CRITICAL

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ⚠Privileges: Requires a low-privilege account
  • ⚠User interaction: Succeeds with passive user activity
  • ✓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-2026-73042/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-2026-73042/poc.json

Affected

Vendors Siyuan Note

Products Siyuan

Weakness (CWE)

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSS vector

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

All CVSS metrics

  • CRITICAL 9.4 v4.0 · CNA Primary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
  • CRITICAL 9 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
  • CRITICAL 9.4 v4.0 · NVD Secondary
    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
  • CRITICAL 9 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

References

Advisories

Sources: NVD · CVE.org · EPSS