CVE-2025-68948: SiYuan: Information Disclosure and Authentication Bypass via Hardcoded Session Secret

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-12-27 · updated 2026-10-13
Weakness: CWE-321

Description

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

siyuan-note siyuan: before 3.5.2 — fixed in 3.5.2

How to fix

Upgrade to a fixed version: siyuan-note siyuan 3.5.2. Check the vendor advisory for mitigations.

References

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