# CVE-2026-110737: Push Endpoint Returns Permissive CORS Headers


- **Severity:** Low 2.3 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026

## What is CVE-2026-110737?

CVE-2026-110737 is a low-severity vulnerability in vaadin flow, published on 27 Oct 2026. 

### Official description

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

Weakness: CWE-942 (Permissive Cross-domain Security Policy with Untrusted Domains), CWE-346 (Origin Validation Error)

## Which versions are affected by CVE-2026-110737?


## How do I fix CVE-2026-110737?

No fix has been published for CVE-2026-110737 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-110737 being exploited?

There is no known exploitation of CVE-2026-110737 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-110737 and fix it if it is affected.

What it is: CVE-2026-110737 is a low-severity vulnerability in vaadin flow, published on 27 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-110737 in the wild and no public exploit code.

Affected product: vaadin flow. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-110737/ (Markdown: https://insights.sbomify.com/CVE-2026-110737/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-110737
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-110737
- OSV: https://osv.dev/vulnerability/CVE-2026-110737

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-110737/
Summaries are generated and may contain mistakes; the official description above is the record.
