How severe is CVE-2021-31408?

CVE-2021-31408 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-31408 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-31408?

CVE-2021-31408 primarily affects Vaadin Flow. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-31408?

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

When was CVE-2021-31408 published?

CVE-2021-31408 was published on 2021-04-23 and last updated on 2026-06-17.

CVE-2021-31408

CVE-2021-31408 is a medium-severity vulnerability in Vaadin Flow with a CVSS 3.x base score of 6.3. 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-613.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 3.3
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-613
Affected product: Vaadin Flow
Published: 2021-04-23
Last modified: 2026-06-17

Description

Authentication.logout() helper in com.vaadin:flow-client versions 5.0.0 prior to 6.0.0 (Vaadin 18), and 6.0.0 through 6.0.4 (Vaadin 19.0.0 through 19.0.3) uses incorrect HTTP method, which, in combination with Spring Security CSRF protection, allows local attackers to access Fusion endpoints after the user attempted to log out.

Frequently asked questions

What is CVE-2021-31408?: Authentication.logout() helper in com.vaadin:flow-client versions 5.0.0 prior to 6.0.0 (Vaadin 18), and 6.0.0 through 6.0.4 (Vaadin 19.0.0 through 19.0.3) uses incorrect HTTP method, which, in combination with Spring Security CSRF protection, allows local attackers to access Fusion endpoints after the user attempted to log out.
How severe is CVE-2021-31408?: CVE-2021-31408 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over local access with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-31408 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-31408?: CVE-2021-31408 primarily affects Vaadin Flow. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-31408?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-31408 published?: CVE-2021-31408 was published on 2021-04-23 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:vaadin:flow:*:*:*:*:*:*:*:*
cpe:2.3:a:vaadin:vaadin:*:*:*:*:*:*:*:*
cpe:2.3:a:vaadin:vaadin:18.0.0:-:*:*:*:*:*:*

More vulnerabilities in Vaadin Flow

CVE-2021-31407 — High (CVSS 8.6): Vulnerability in OSGi integration in com.vaadin:flow-server versions 1.2.0 through 2.4.7 (Vaadin 12.0.0 through…
CVE-2021-31405 — High (CVSS 7.5): Unsafe validation RegEx in EmailField component in com.vaadin:vaadin-text-field-flow versions 2.0.4 through 2.3.2…
CVE-2021-31411 — Medium (CVSS 6.3): Insecure temporary directory usage in frontend build functionality of com.vaadin:flow-server versions 2.0.9 through…
CVE-2019-25027 — Medium (CVSS 6.1): Missing output sanitization in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through 1.0.10…
CVE-2020-36321 — Medium (CVSS 5.9): Improper URL validation in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.4.1 (Vaadin…
CVE-2021-31412 — Medium (CVSS 5.3): Improper sanitization of path in default RouteNotFoundError view in com.vaadin:flow-server versions 1.0.0 through…

All CVEs affecting Vaadin Flow →

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