Critical severity · published Aug 21, 2026
CVE-2026-77086
SiYuan before v3.7.4 Path Traversal via packageName
9.1
CVSS
1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 63% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
siyuan · siyuan-note
before 3.7.4 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-77086
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-77086
vendor-advisory
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-wr4w-7vjm-mmx3
third-party-advisory
https://www.vulncheck.com/advisories/siyuan-before-path-traversal-via-packagename
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