High severity · published Aug 30, 2026
CVE-2026-82654
SiYuan before v3.8.1 Stored XSS via block name
8.9
CVSS
0.4%
EPSS
No
On KEV
Description
SiYuan before v3.8.1 fails to properly escape block name, alias, and memo fields in hint, backlink, and breadcrumb rendering functions. Attackers can set a block's name to contain HTML/script tags that execute when another user views documents referencing or displaying that block.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 30% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SI
siyuan · siyuan-note
before 3.8.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-82654
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-82654
github.com
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-hf87-qh3j-3p88
www.vulncheck.com
https://www.vulncheck.com/advisories/siyuan-before-3.8.1-stored-xss-via-block-name
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