How severe is CVE-2021-33611?

CVE-2021-33611 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-2021-33611 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33611?

CVE-2021-33611 primarily affects Vaadin. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-33611?

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

When was CVE-2021-33611 published?

CVE-2021-33611 was published on 2021-11-02 and last updated on 2026-06-17.

CVE-2021-33611

CVE-2021-33611 is a medium-severity vulnerability in Vaadin 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 v2: 4.3
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Vaadin
Published: 2021-11-02
Last modified: 2026-06-17

Description

Missing output sanitization in test sources in org.webjars.bowergithub.vaadin:vaadin-menu-bar versions 1.0.0 through 1.2.0 (Vaadin 14.0.0 through 14.4.4) allows remote attackers to execute malicious JavaScript in browser by opening crafted URL

Frequently asked questions

What is CVE-2021-33611?: Missing output sanitization in test sources in org.webjars.bowergithub.vaadin:vaadin-menu-bar versions 1.0.0 through 1.2.0 (Vaadin 14.0.0 through 14.4.4) allows remote attackers to execute malicious JavaScript in browser by opening crafted URL
How severe is CVE-2021-33611?: CVE-2021-33611 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-2021-33611 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33611?: CVE-2021-33611 primarily affects Vaadin. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-33611?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-33611 published?: CVE-2021-33611 was published on 2021-11-02 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:vaadin:vaadin:*:*:*:*:*:*:*:*
cpe:2.3:a:vaadin:vaadin-menu-bar:*:*:*:*:*:*:*:*

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