# CVE-2026-73053 — siyuan-note siyuan

> As of 2026-08-15, CVE-2026-73053 is a CRITICAL-severity vulnerability in siyuan-note siyuan, CVSS v3.1 9, EPSS 0.2% (20.9th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-73053 as of 2026-08-15; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-15

## What is CVE-2026-73053?

SiYuan versions before v3.7.4 contain a cross-site scripting vulnerability in the unicode2Emoji function that fails to sanitize codepoint branch output. Attackers can craft document icons with hex-encoded markup that executes in the renderer with Node integration enabled, achieving arbitrary code execution on the host system.

The record classifies CVE-2026-73053 under weakness class [CWE-79](https://intel.threadlinqs.com/cwe/CWE-79). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs a user to take an action first, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 51 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 9 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H`)
- **CVSS v4.0 base score:** 9.4 (`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`)
- **EPSS (FIRST):** 0.2% probability of exploitation in the next 30 days, higher than 20.9% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-15

## Is CVE-2026-73053 being exploited?

It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [siyuan-note](https://intel.threadlinqs.com/vendors/siyuan-note): siyuan

## How to fix CVE-2026-73053

No vendor patch reference has been recorded for CVE-2026-73053 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-73053

No threat campaign in the Threadlinqs corpus currently references CVE-2026-73053, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-16.

**Vendor advisory and patch**

- [github.com — vendor advisory](https://github.com/siyuan-note/siyuan/security/advisories/GHSA-vx5w-qrvp-mmcq)

**Third-party advisory**

- [vulncheck.com — third party advisory](https://www.vulncheck.com/advisories/siyuan-before-cross-site-scripting-via-unicode2emoji)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-73053
Full detection coverage and IOCs for threats exploiting CVE-2026-73053 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp