CVE-2026-84803

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

Not scored by EPSS

EPSS percentile

Not scored by EPSS

NVD base score

8.6 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-09-02.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-02 11:11Z17 HR AGO

Last updated

2026-09-02 13:54Z15 HR AGO

Reserved

2026-09-02

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.6)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base

Data version

5.2

Document digest

81c7ef7bcb2a73ae6d43f91a4721a5bc123ec004c9700b494df87f791203cc62

• github.comGitHub Security Advisory (GHSA-7h8j-qw37-w46g)https://github.com/siyuan-note/siyuan/security/advisories/GHSA-7h8j-qw37-w46gvendor-advisory
• www.vulncheck.comVulnCheck Advisory: SiYuan before v3.8.2 Stored XSS via incomplete asset blocklisthttps://www.vulncheck.com/advisories/siyuan-before-3.8.2-stored-xss-via-incomplete-asset-blocklistthird-party-advisory