CVE-2025-68948: b3log Siyuan

High severity, CVSS 8.1. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• b3log Siyuan: before 3.5.2 (fixed in 3.5.2)

Published 2025-12-27. Last modified 2026-06-17.