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CRITICAL

CVE-2026-77086

CVSS v3

9.1

CRITICAL

EPSS Score

1.0 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

Technical details

Published
2026-08-21
Last Modified
2026-08-21

Frequently asked questions

What is CVE-2026-77086?

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

Is CVE-2026-77086 actively exploited?

Active exploitation of CVE-2026-77086 has not been confirmed. Its EPSS score was 1.0% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-77086?

CVE-2026-77086 has a CVSS v3 base score of 9.1 (CRITICAL severity).

Is CVE-2026-77086 affecting your environment?

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