CVE-2026-109309: SiYuan v3.7.0 before v3.8.6 Arbitrary File Read via Plugin ResponseFile.Path

Q: Which deployments are exposed?

SiYuan versions from v3.7.0 before v3.8.6 are affected. Exposure requires the kernel's private plugin HTTP server to process a response from a malicious kernel plugin.

Q: What does an attacker need to exploit this issue?

An attacker needs to supply a malicious kernel plugin and induce a user interaction, as reflected by the UI:R vector. The plugin can provide an absolute path in ResponseFile.Path.

Q: What data could be read?

The attacker can read any file that is readable by the SiYuan process. The advisory specifically identifies the API token and conf.json as potential targets.

Q: How can I determine whether I may be affected?

Check whether the deployed SiYuan version is v3.7.0 or later but earlier than v3.8.6, and review installed or proposed kernel plugins for ResponseFile.Path values that use absolute paths.

Published Oct 12, 2026

Updated

SiYuan v3.7.0 before v3.8.6 contains an absolute path traversal vulnerability in the kernel's private plugin HTTP server, which passes a kernel plugin handler's ResponseFile.Path to gin's Context.File without validation. Attackers supplying a malicious kernel plugin can return an absolute path to read any file readable by the SiYuan process, including the API token and conf.json.

Affected Software

1 affected component

SiYuan SiYuan>=3.7.0<3.8.6

Event History

Oct 12, 2026

CVE Published

via MITRE·04:05 PM

Data Sourced

via MITRE·04:05 PM

DescriptionSeverityWeakness

Data Sourced

via NVD·05:17 PM

DescriptionSeverityWeakness

Frequently Asked Questions

Which deployments are exposed?

SiYuan versions from v3.7.0 before v3.8.6 are affected. Exposure requires the kernel's private plugin HTTP server to process a response from a malicious kernel plugin.

What does an attacker need to exploit this issue?

An attacker needs to supply a malicious kernel plugin and induce a user interaction, as reflected by the UI:R vector. The plugin can provide an absolute path in ResponseFile.Path.

What data could be read?

The attacker can read any file that is readable by the SiYuan process. The advisory specifically identifies the API token and conf.json as potential targets.

How can I determine whether I may be affected?

Check whether the deployed SiYuan version is v3.7.0 or later but earlier than v3.8.6, and review installed or proposed kernel plugins for ResponseFile.Path values that use absolute paths.

CVE-2026-109309: SiYuan v3.7.0 before v3.8.6 Arbitrary File Read via Plugin ResponseFile.Path

Affected Software

Event History

Frequently Asked Questions

Which deployments are exposed?

What does an attacker need to exploit this issue?

What data could be read?

How can I determine whether I may be affected?

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Frequently Asked Questions

Which deployments are exposed?

What does an attacker need to exploit this issue?

What data could be read?

How can I determine whether I may be affected?