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HIGH

CVE-2026-100636

CVSS v3

7.6

HIGH

EPSS Score

0.5 %

exploit probability, as of 2026-09-28

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences to escape the export directory and overwrite index.html in any pre-existing kernel-writable location, enabling stored XSS or workspace defacement.

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L
Published
2026-09-26
Last Modified
2026-09-26

Frequently asked questions

What is CVE-2026-100636?

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the exportBrowserHTML endpoint that allows authenticated administrators to write arbitrary HTML content to index.html outside the workspace directory. Attackers can supply a folder parameter with directory traversal sequences to escape the export directory and overwrite index.html in any pre-existing kernel-writable location, enabling stored XSS or workspace defacement.

Is CVE-2026-100636 actively exploited?

Active exploitation of CVE-2026-100636 has not been confirmed. Its EPSS score was 0.5% on 2026-09-28, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-100636?

CVE-2026-100636 has a CVSS v3 base score of 7.6 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L.

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