🛡️ CVE-2026-0858 — plantuml

🟡 CVSS 6.1 — Medium ✅ No Known Exploit CWE-79 NVD

6.1

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

PlantUML is vulnerable to Stored XSS due to insufficient sanitization of interactive attributes in GraphViz diagrams

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 malicious JavaScript into generated SVG output, leading to arbitrary script execution in the context of applications that render the SVG.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.

Weakness class

CVE-2026-0858 is classified as CWE-79: Cross-site Scripting (XSS). User-supplied data is written into a page without escaping, so attacker script runs in the browser of anyone who views it.

Affected software

CVE-2026-0858 is recorded against 2 packages.

net.sourceforge.plantuml:plantuml (fixed in 1.2026.0)
plantuml (fixed in 1.2026.0)

Timeline and source

Published on 16 January 2026 and last revised on 3 February 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
github.com (Web)
security.snyk.io (Web)

CVE-2026-0858 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Debian Ubuntu

Details

Severity LOW

CVSS Score 6.1

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE CWE-79

Public Exploit ✅ No

Source NVD

Published 2026-01-16

Updated 2026-08-20

Modified 2026-02-03

Fix URL https://github.com/plantuml/plantuml/commit/6826315db092d2e432aeab1a0894e08017c6e4bd

Affected Packages

Software	From version	Fixed in
net.sourceforge.plantuml:plantuml	—	1.2026.0
plantuml	—	1.2026.0

References

ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2026-0858

WEB https://github.com/plantuml/plantuml/commit/6826315db092d2e432aeab1a0894e08017c6e4bd

PACKAGE https://github.com/plantuml/plantuml

WEB https://github.com/plantuml/plantuml/releases/tag/v1.2026.0

WEB https://security.snyk.io/vuln/SNYK-JAVA-NETSOURCEFORGEPLANTUML-14552230

🔗 NVD 🔗 Mitre ✅ Fix / Advisory

Similar Threats

Medium CVE-2023-3431
Critical CVE-2023-3432

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