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HIGH

CVE-2026-100638

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 setNotebookIcon endpoint that allows authenticated administrators to create arbitrary directory trees and write files outside the workspace boundary. Attackers can supply directory traversal sequences in the notebook parameter to escape the workspace data directory and write conf.json files to arbitrary locations accessible by the kernel process.

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-2026-100638?

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the setNotebookIcon endpoint that allows authenticated administrators to create arbitrary directory trees and write files outside the workspace boundary. Attackers can supply directory traversal sequences in the notebook parameter to escape the workspace data directory and write conf.json files to arbitrary locations accessible by the kernel process.

Is CVE-2026-100638 actively exploited?

Active exploitation of CVE-2026-100638 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-2026-100638?

CVE-2026-100638 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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