CVE-2020-36523: A vulnerability was found in PlantUML 6.43

Routine

LOW 3.5DOWNGRADE

CVE-2020-36523 is a low-severity flaw (CVSS 3.5) affecting plantuml. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability was found in PlantUML 6.43. It has been declared as problematic. Affected by this vulnerability is the component Database Information Macro. The manipulation leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed to the public and may be used.

Why this priority

Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	3.5 (Low)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-79
Published	2022-06-07
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: avono

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-06-07 18:15 UTCPublished CVE record published
2026-06-17 03:15 UTCUpdated Record last modified

avono plantuml DOWNGRADE

Affected: 6.43

Fixed in: no fixed release known

Safe to downgrade to: a release before 6.43

1. Check installed version

apt-cache policy plantuml || rpm -q plantuml || plantuml --version

2. No fixed release: DOWNGRADE to a release before 6.43 (Debian / Ubuntu)

apt-cache madison plantuml sudo apt install plantuml=<VERSION_BEFORE_6.43> sudo apt-mark hold plantuml

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list plantuml sudo dnf downgrade plantuml-<VERSION_BEFORE_6.43> sudo dnf versionlock add plantuml

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-36523?

plantuml: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-36523 being exploited?

CVE-2020-36523 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2020-36523 affect?

CVE-2020-36523 affects plantuml. Severity is low (CVSS 3.5). A vulnerability was found in PlantUML 6.43. It has been declared as problematic. Affected by this vulnerability is the component Database Information Macro. The manipulation leads to cross site scripting. The attack can be launched remotely

How urgent is CVE-2020-36523?

Priority 29/100. Public exploit reference

Related CVEs

CVE-2026-0858 MEDIUM 6.1 UPGRADE Versions of the package net.sourceforge.plantuml:plantuml before 1.2026.0 are vulnerable to Stored XSS due to
CVE-2023-3432 CRITICAL 10.0 UPGRADE MITIGATE Server-Side Request Forgery (SSRF) in GitHub repository plantuml/plantuml prior to 1.2023.9.
CVE-2023-3431 MEDIUM 5.3 UPGRADE MITIGATE Improper Access Control in GitHub repository plantuml/plantuml prior to 1.2023.9.
CVE-2022-1379 CRITICAL 9.1 UPGRADE MITIGATE URL Restriction Bypass in GitHub repository plantuml/plantuml prior to V1.2022.5
CVE-2022-1231 MEDIUM 6.1 UPGRADE MITIGATE XSS via Embedded SVG in SVG Diagram Format in GitHub repository plantuml/plantuml prior to 1.2022.4

References

← Back to latest CVEs