CVE-2026-110737 PUBLISHED

Push Endpoint Returns Permissive CORS Headers

Assigner: Vaadin
Reserved: 14.10.2026 Published: 27.10.2026 Updated: 27.10.2026

The push endpoint of a Vaadin application that uses server push reflects the request Origin into the Access-Control-Allow-Origin response header and allows credentials, because Flow configures Atmosphere with DROP_ACCESS_CONTROL_ALLOW_ORIGIN_HEADER set to false and its CorsInterceptor then echoes whatever Origin the request carries. A page on any origin can therefore make a cross origin request to that endpoint with the user's cookies and read the response, although reading anything useful also requires the push identifier of that session. Applications that do not use @Push are not affected, and neither is the WebSocket transport. The behaviour was introduced in January 2015 and is present in every Flow release and in Vaadin Framework from 7.1.0, which is when push was added.

Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include:

Product version Vaadin 14.14.0 - 14.14.7 Vaadin 23.6.0 - 23.6.16 Vaadin 24.4.0 - 24.4.25 Vaadin 24.5.0 - 24.5.15 Vaadin 24.6.0 - 24.6.13 Vaadin 24.7.0 - 24.7.16 Vaadin 24.8.0 - 24.8.17 Vaadin 24.9.0 - 24.9.23 Vaadin 24.10.0 - 24.10.11 Vaadin 25.0.0 - 25.0.13 Vaadin 25.1.0 - 25.1.13 Vaadin 25.2.0 - 25.2.10 Vaadin 25.3.0 - 25.3.2 Vaadin Framework 7.1.0 - 7.7.54 Vaadin Framework 8.0.0 - 8.32.1

Mitigation Upgrade to 14.14.8 Upgrade to 23.6.17 Upgrade to 24.4.26 Upgrade to 24.7.17 Upgrade to 24.7.17 Upgrade to 24.7.17 Upgrade to 24.9.24 Upgrade to 24.9.24 Upgrade to 24.10.12 Upgrade to 25.2.11 Upgrade to 25.2.11 Upgrade to 25.2.11 Upgrade to 25.3.3 Upgrade to 7.7.55 Upgrade to 8.32.2

Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 14, 23, 24, 25 version.

Artifacts under com.vaadin Maven coordinates / Vulnerable versions / Fixed version vaadin / 14.14.0 - 14.14.7 / >=14.14.8 vaadin / 23.6.0 - 23.6.16 / >=23.6.17 vaadin / 24.4.0 - 24.4.25 / >=24.4.26 vaadin / 24.5.0 - 24.5.15 / >=24.7.17 vaadin / 24.6.0 - 24.6.13 / >=24.7.17 vaadin / 24.7.0 - 24.7.16 / >=24.7.17 vaadin / 24.8.0 - 24.8.17 / >=24.9.24 vaadin / 24.9.0 - 24.9.23 / >=24.9.24 vaadin / 24.10.0 - 24.10.11 / >=24.10.12 vaadin / 25.0.0 - 25.0.13 / >=25.2.11 vaadin / 25.1.0 - 25.1.13 / >=25.2.11 vaadin / 25.2.0 - 25.2.10 / >=25.2.11 vaadin / 25.3.0 - 25.3.2 / >=25.3.3 vaadin-core / 14.14.0 - 14.14.7 / >=14.14.8 vaadin-core / 23.6.0 - 23.6.16 / >=23.6.17 vaadin-core / 24.4.0 - 24.4.25 / >=24.4.26 vaadin-core / 24.5.0 - 24.5.15 / >=24.7.17 vaadin-core / 24.6.0 - 24.6.13 / >=24.7.17 vaadin-core / 24.7.0 - 24.7.16 / >=24.7.17 vaadin-core / 24.8.0 - 24.8.17 / >=24.9.24 vaadin-core / 24.9.0 - 24.9.23 / >=24.9.24 vaadin-core / 24.10.0 - 24.10.11 / >=24.10.12 vaadin-core / 25.0.0 - 25.0.13 / >=25.2.11 vaadin-core / 25.1.0 - 25.1.13 / >=25.2.11 vaadin-core / 25.2.0 - 25.2.10 / >=25.2.11 vaadin-core / 25.3.0 - 25.3.2 / >=25.3.3 flow-server / 2.13.0 - 2.13.7 / >=2.13.8 flow-server / 23.6.0 - 23.6.15 / >=23.6.16 flow-server / 24.4.0 - 24.4.18 / >=24.4.19 flow-server / 24.5.0 - 24.5.17 / >=24.7.17 flow-server / 24.6.0 - 24.6.14 / >=24.7.17 flow-server / 24.7.0 - 24.7.15 / >=24.7.16 flow-server / 24.8.0 - 24.8.16 / >=24.9.24 flow-server / 24.9.0 - 24.9.28 / >=24.9.29 flow-server / 24.10.0 - 24.10.14 / >=24.10.15 flow-server / 25.0.0 - 25.0.15 / >=25.2.11 flow-server / 25.1.0 - 25.1.18 / >=25.1.19 flow-server / 25.2.0 - 25.2.12 / >=25.2.13 flow-server / 25.3.0 - 25.3.3 / >=25.3.4 vaadin-server / 7.1.0 - 7.7.54 / >=7.7.55 vaadin-server / 8.0.0 - 8.32.1 / >=8.32.2 vaadin-server-mpr-jakarta / 7.7.36 - 7.7.54 / >=7.7.55 vaadin-server-mpr-jakarta / 8.18.0 - 8.32.1 / >=8.32.2

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS Score: 2.3

Product Status

Vendor vaadin
Product vaadin
Versions Default: unaffected
  • affected from 14.14.0 to 14.14.8 (excl.)
  • affected from 23.6.0 to 23.6.17 (excl.)
  • affected from 24.4.0 to 24.4.26 (excl.)
  • affected from 24.5.0 to 24.5.15 (incl.)
  • affected from 24.6.0 to 24.6.13 (incl.)
  • affected from 24.7.0 to 24.7.17 (excl.)
  • affected from 24.8.0 to 24.8.17 (incl.)
  • affected from 24.9.0 to 24.9.24 (excl.)
  • affected from 24.10.0 to 24.10.12 (excl.)
  • affected from 25.0.0 to 25.0.13 (incl.)
  • affected from 25.1.0 to 25.1.13 (incl.)
  • affected from 25.2.0 to 25.2.11 (excl.)
  • affected from 25.3.0 to 25.3.3 (excl.)
Vendor vaadin
Product vaadin
Versions Default: unaffected
  • affected from 14.14.0 to 14.14.8 (excl.)
  • affected from 23.6.0 to 23.6.17 (excl.)
  • affected from 24.4.0 to 24.4.26 (excl.)
  • affected from 24.5.0 to 24.5.15 (incl.)
  • affected from 24.6.0 to 24.6.13 (incl.)
  • affected from 24.7.0 to 24.7.17 (excl.)
  • affected from 24.8.0 to 24.8.17 (incl.)
  • affected from 24.9.0 to 24.9.24 (excl.)
  • affected from 24.10.0 to 24.10.12 (excl.)
  • affected from 25.0.0 to 25.0.13 (incl.)
  • affected from 25.1.0 to 25.1.13 (incl.)
  • affected from 25.2.0 to 25.2.11 (excl.)
  • affected from 25.3.0 to 25.3.3 (excl.)
Vendor vaadin
Product flow
Versions Default: unaffected
  • affected from 2.13.0 to 2.13.8 (excl.)
  • affected from 23.6.0 to 23.6.16 (excl.)
  • affected from 24.4.0 to 24.4.19 (excl.)
  • affected from 24.5.0 to 24.5.17 (incl.)
  • affected from 24.6.0 to 24.6.14 (incl.)
  • affected from 24.7.0 to 24.7.16 (excl.)
  • affected from 24.8.0 to 24.8.16 (incl.)
  • affected from 24.9.0 to 24.9.29 (excl.)
  • affected from 24.10.0 to 24.10.15 (excl.)
  • affected from 25.0.0 to 25.0.15 (incl.)
  • affected from 25.1.0 to 25.1.19 (excl.)
  • affected from 25.2.0 to 25.2.13 (excl.)
  • affected from 25.3.0 to 25.3.4 (excl.)
Vendor vaadin
Product framework
Versions Default: unaffected
  • affected from 7.1.0 to 7.7.55 (excl.)
  • affected from 8.0.0 to 8.32.2 (excl.)
Vendor vaadin
Product framework
Versions Default: unaffected
  • affected from 7.7.36 to 7.7.55 (excl.)
  • affected from 8.18.0 to 8.32.2 (excl.)

Workarounds

Set the servlet init parameter org.atmosphere.cpr.dropAccessControlAllowOriginHeader to true on the Vaadin servlet, which stops the header being emitted without upgrading. In a Spring Boot application the Vaadin servlet has to be registered explicitly for the parameter to be applied.

Solutions

Users of affected versions should apply the following mitigation or upgrade.

References

Problem Types

  • CWE-942 Permissive Cross-domain Policy with Untrusted Domains CWE
  • CWE-346 Origin Validation Error CWE

Impacts

  • CAPEC-468 Generic Cross-Browser Cross-Domain Theft