SiYuan anfällig für Arbitrary file Read / SSRF in github.com/siyuan-note/siyuan/kernel

The SSRF vulnerability in SiYuan Kernel allows an attacker to craft malicious requests that the server will execute, effectively acting as a proxy for the attacker. This can be exploited to read files that the server process has access to, including configuration files, database credentials, or other sensitive data. Successful exploitation could lead to the exposure of internal system information, enabling further attacks. While direct remote code execution is unlikely, the ability to read arbitrary files significantly expands the attack surface and could be a stepping stone for more sophisticated attacks. The potential blast radius depends on the server's configuration and the permissions of the SiYuan Kernel process.

Organizations and individuals using SiYuan for note-taking and knowledge management are at risk, particularly those running self-hosted instances or deployments where the SiYuan Kernel is exposed to external networks. Shared hosting environments where multiple users share the same SiYuan instance are also at increased risk.

• go / server: Examine application logs for unusual outbound HTTP requests, particularly those originating from internal IP addresses or using unusual protocols. Use netstat or ss to monitor connections and identify suspicious activity.

ss -t tcp -4 -n | grep <internal_ip_address>

• generic web: Monitor access logs for requests to internal resources or unusual file paths. Check response headers for signs of SSRF exploitation.

grep "/internal/path" /var/log/apache2/access.log

1. 2026-02-03Disclosure

   disclosure

1. Reserviert2026-01-16
2. Veröffentlicht2026-02-03
3. Geändert2026-03-03
4. EPSS aktualisiert2026-03-23

The primary mitigation for CVE-2026-23850 is to immediately upgrade SiYuan Kernel to version 0.0.0-20260118092326-b2274baba2e1 or later. If upgrading is not immediately feasible, consider implementing temporary workarounds such as restricting outbound network access for the SiYuan Kernel process using a firewall or network segmentation. Review and harden the server's configuration to minimize the potential impact of file reads. Monitor access logs for unusual outbound requests originating from the SiYuan Kernel process. After upgrading, confirm the fix by attempting a controlled SSRF request to a non-sensitive internal resource and verifying that it is denied.