# CVE-2026-33476: SiYuan - Path Traversal

> Live exploitation tracking for CVE-2026-33476 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2026-33476

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 7.5
- **Public exploit available:** Yes
- **Affected products:** SiYuan
- **Weaknesses:** CWE-22 (Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')); CWE-73 (External Control of File Name or Path)
- **Tags:** web_application

## Description

SiYuan is a personal knowledge management system. Prior to version 3.6.2, the SiYuan kernel exposes an unauthenticated file-serving endpoint under `/appearance/*filepath.` Due to improper path sanitization, attackers can perform directory traversal and read arbitrary files accessible to the server process. Authentication checks explicitly exclude this endpoint, allowing exploitation without valid credentials. Version 3.6.2 fixes this issue.

## CrowdSec analysis

[CVE-2026-33476](https://euvd.enisa.europa.eu/vulnerability/CVE-2026-33476) is a path traversal vulnerability in SiYuan prior to version 3.6.2, where an unauthenticated file-serving endpoint fails to properly sanitize file paths. This flaw allows remote attackers to read arbitrary files on the server without authentication, potentially exposing sensitive information and system data. The vulnerability is addressed in version 3.6.2.

CrowdSec has been tracking this vulnerability and its exploits since 24th of June 2026.

CrowdSec network data shows that most actors exploiting CVE-2026-33476 rely on broad, untargeted scans with minimal filtering. The activity is largely automated and opportunistic in nature.
CrowdSec network telemetry also shows that exploitation of CVE-2026-33476 has significantly declined over the past week. Attack volumes are well below the long-term average, suggesting attackers are rapidly losing interest. The vulnerability appears to be falling out of active use across most threat landscapes.

Attackers exploit the unauthenticated `/appearance/` endpoint by sending requests with path traversal sequences (e.g., `/appearance/langs/../../`) to access sensitive files on the server. This allows arbitrary file read without authentication on vulnerable SiYuan instances.

## Timeline

- 2026-03-20: CVE Published. CVE-2026-33476 is published to NVD.
- 2026-06-24: Rule Released. CrowdSec releases a rule to detect CVE-2026-33476 exploitation attempts against the CrowdSec Network.
- 2026-07-20: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2026-33476 for the first time.

## References

- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hhgj-gg9h-rjp7
- https://github.com/siyuan-note/siyuan/commit/009bb598b3beccc972aa5f1ed88b3b224326bf2a
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-33476.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2026-33476) follows observed exploitation activity for CVE-2026-33476. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.