CVE-2019-25027Network attack vector

JavaScript execution via unsanitized error-path reflection

Published Apr 23, 2021 · Updated Sep 17, 2024

Reflected XSS in Vaadin Framework 10.0.0 through 13.0.5 allows remote attackers to execute JavaScript through a crafted URL. The default RouteNotFoundError view inserts the attacker-controlled request path into its HTML error template without output sanitization. No authentication is required, but a user must open the crafted URL; script execution occurs in that user's browser under the affected application's origin.

CVSS severity6.1
Medium
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Vaadin Framework 10.0.0 through 13.0.5 allows remote attackers to execute JavaScript through a crafted URL. The default RouteNotFoundError view inserts the attacker-controlled request path into its HTML error template without output sanitization. No authentication is required, but a user must open the crafted URL; script execution occurs in that user's browser under the affected application's origin.

The record

CVE
CVE-2019-25027
Published
Apr 23, 2021
Updated
Sep 17, 2024
Vendor
Vaadin
Product
Flow Server
Classifications
CWE-81, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0 <* changes=[{"at":"1.1.0","status":"affected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Vaadin · Flow Serverversion=1.0.0 <* changes=[{"at":"1.1.0","status":"affected"}]
Vaadin · Vaadin Frameworkversion=10.0.0 <* changes=[{"at":"11.0.0","status":"affected"}]

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N
6.1Vaadin Ltd.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-81Improper Neutralization of Script in an Error Message Web Page
T1204.001Malicious Link

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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