How severe is CVE-2026-0858?

CVE-2026-0858 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-0858 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-0858?

CVE-2026-0858 affects Plantuml. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-0858?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-0858 have an EU (EUVD) identifier?

Yes. CVE-2026-0858 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2918.

When was CVE-2026-0858 published?

CVE-2026-0858 was published on 2026-01-16 and last updated on 2026-06-17.

CVE-2026-0858

CVE-2026-0858 is a medium-severity vulnerability in Plantuml with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 2.0
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-2918
Weakness: CWE-79
Affected product: Plantuml
Published: 2026-01-16
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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 malicious JavaScript into generated SVG output, leading to arbitrary script execution in the context of applications that render the SVG.
How severe is CVE-2026-0858?: CVE-2026-0858 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-0858 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-0858?: CVE-2026-0858 affects Plantuml. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-0858?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-0858 have an EU (EUVD) identifier?: Yes. CVE-2026-0858 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-2918.
When was CVE-2026-0858 published?: CVE-2026-0858 was published on 2026-01-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:plantuml:plantuml:*:*:*:*:*:*:*:*

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