SiYuan is self-hosted, open source personal knowledge management software. In versions 3.5.1 and prior, the SiYuan Note application utilizes a hardcoded cryptographic secret for its session store. This unsafe practice renders the session encryption ineffective. Since the sensitive AccessAuthCode is stored within the session cookie, an attacker who intercepts or obtains a user's encrypted session cookie (e.g., via session hijacking) can locally decrypt it using the public key. Once decrypted, the attacker can retrieve the AccessAuthCode in plain text and use it to authenticate or take over the session.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.1, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 1 product from b3log organizations running these solutions should prioritize assessment and patching.
Reported in 2025, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2025-12-27T01:15:42.720
2026-01-02T19:30:38.353
Analyzed
CVSSv3.1: 8.1 (HIGH)
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For b3log's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.