9.4

CVE-2026-74800: siyuan-note siyuan Cross-site Scripting

CVSS: 9.4v4.0CriticalDeferred
Published 17-08-2026Last modified 17-08-2026
Open JSON

Vulnerability summary

CVE-2026-74800 is a critical (CVSS 9.4) Cross-site Scripting vulnerability in siyuan-note siyuan. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.6% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.4/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.43%
0%100%
Low · +0.14 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 17-08-2026
    PublishedVulnerability first disclosed.
  2. 17-08-2026
    Last modifiedVulnerability information updated.

Description

SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full kernel API access when the workspace owner opens the asset link.

CVSS metrics

4 scores · 2 sources · 2 versions

EPSS trend

Probability

0.43%

Chance of exploitation in the next 30 days

Percentile

36%

Versus all other CVEs

30-day change

+0.14 pp

From 0.29% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.43%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Siyuan-note1 product

1 vendor · 1 product

References

2 links