CVE-2026-87811CWE-79cross-site-scripting

CVE-2026-87811

High · published September 9, 2026

CVSS v3.1
7.3
EPSS
0%
Percentile
29.3
In the wild
Unconfirmed
What it is

SiYuan before v3.8.2 inserts persisted notebook template paths into HTML input value attributes without proper attribute encoding. Attackers can craft malicious template paths that break out of the attribute context and execute JavaScript when a victim opens notebook configuration, enabling same-origin API requests and application state manipulation.

The record
Technical detail
CVSS v3.1
7.3 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
CVSS v4.0
8.4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
EPSS
0.00367 · 29.3th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-09-09T16:17Z
References (2)
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-v6wf-r2gr-rrgf · [email protected]https://www.vulncheck.com/advisories/siyuan-before-3.8.2-stored-xss-via-notebook-template-paths · [email protected]
EPSS history
Timeline
  • 11 SEP 03:19Z
    EPSS moved — → 0%
    epss
  • 09 SEP 11:20Z
    SiYuan before v3.8.2 Stored XSS via notebook template paths
    cvelistv5