CVE-2026-62204: SiYuan before v3.7.4 Plugin Overwrite via Bazaar Install

Published Aug 22, 2026
·
Updated

SiYuan versions before v3.7.4 fail to validate that packageName matches the downloaded package content in bazaar install endpoints. Attackers with same-origin access can overwrite existing trusted plugins by supplying mismatched packageName and repoURL parameters, achieving persistence across application restarts.

Affected Software

1 affected component
SiYuan SiYuan<v3.7.4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 3.7.4
  2. Configuration

    Upgrade SiYuan to v3.7.4+ so the bazaar install endpoints validate that the submitted packageName matches the downloaded package content (mitigates overwriting trusted plugins via mismatched packageName and repoURL).

    SiYuan bazaar install endpoints packageName vs downloaded package content validation = enforced

Event History

Aug 22, 2026
CVE Published
via MITRE·12:26 PM
Data Sourced
via MITRE·12:26 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What access does an attacker need to exploit this issue?

The attacker needs same-origin access, low privileges, and user interaction. Exploitation also has high attack complexity and requires access to the bazaar install endpoints.

2

Which installations are affected?

SiYuan versions before v3.7.4 are affected. The issue concerns installations where the bazaar install functionality can be used to install packages.

3

What is the practical impact of successful exploitation?

An attacker can overwrite an existing trusted plugin by supplying mismatched packageName and repoURL parameters. The replaced plugin can persist across application restarts.

4

How can I tell whether I may already be affected?

Review installed trusted plugins for unexpected replacement or content changes, especially after bazaar installation activity. Check whether the SiYuan version is earlier than v3.7.4.

Contact

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