What is CVE-2026-0858?

CVE-2026-0858 is a medium-severity vulnerability in Plantuml, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-01-16.

How severe is CVE-2026-0858?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Plantuml

CVE-2026-0858

Versions of the package net.sourceforge.plantuml:plantuml before 1.2026.0 are vulnerable to Stored XSS due to insufficient sanitization of interactive attributes in GraphViz diagrams. As a result, a crafted PlantUML diagram can inject mali…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.003 (22.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Plantuml
N/a Net.sourceforge.plantuml:plantuml — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

report@snyk.io (Patch, Vendor Advisory)
report@snyk.io (Patch)
report@snyk.io (Release Notes)

Frequently asked questions

What is CVE-2026-0858?: CVE-2026-0858 is a medium-severity vulnerability in Plantuml, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-01-16.
How severe is CVE-2026-0858?: Medium severity. CVSS v3 base score is 6.1 out of 10.