CVE-2026-110737 — Push Endpoint Returns Permissive CORS Headers
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
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Vaadin Flow, Vaadin Framework, Vaadin Vaadin).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Vaadin | Flow |
≥ 25.3.0 and < 25.3.4≥ 25.2.0 and < 25.2.13≥ 25.1.0 and < 25.1.19≥ 25.0.0 and ≤ 25.0.15≥ 24.10.0 and < 24.10.15≥ 24.9.0 and < 24.9.29≥ 24.8.0 and ≤ 24.8.16≥ 24.7.0 and < 24.7.16 and 5 more≥ 24.6.0 and ≤ 24.6.14≥ 24.5.0 and ≤ 24.5.17≥ 24.4.0 and < 24.4.19≥ 23.6.0 and < 23.6.16≥ 2.13.0 and < 2.13.8 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Vaadin | Framework | ≥ 7.7.36 and < 7.7.55≥ 8.18.0 and < 8.32.2≥ 8.0.0 and < 8.32.2≥ 7.1.0 and < 7.7.55 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Vaadin | Vaadin |
≥ 14.14.0 and < 14.14.8≥ 25.3.0 and < 25.3.3≥ 25.2.0 and < 25.2.11≥ 25.1.0 and ≤ 25.1.13≥ 25.0.0 and ≤ 25.0.13≥ 24.10.0 and < 24.10.12≥ 24.9.0 and < 24.9.24≥ 24.8.0 and ≤ 24.8.17 and 5 more≥ 24.7.0 and < 24.7.17≥ 24.6.0 and ≤ 24.6.13≥ 24.5.0 and ≤ 24.5.15≥ 24.4.0 and < 24.4.26≥ 23.6.0 and < 23.6.17 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 2.3 | CVSS 4.0 | Low | — | — | security@vaadin.com via NIST National Vulnerability Database |
| 2.3 | CVSS 4.0 | Low | — | — | Vaadin via CVE Program (cve.org) e CISA ADP |
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: security@vaadin.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 28, 2026 → Oct 30, 2026 · 3 reading(s) · max 0.20%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Timeline
What happened to this CVE, newest first.
- 2026
- Source status changed · Received → Awaiting Analysis
- Source status changed · Published → Received
- Record published
- CVSS changed · 2.3
- Source status changed · → Published
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× Official description updated · Oct 27, 2026 – Oct 27, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-110803 Session Lock Leak on an Invalid UI Id Allows Denial of Service in Vaadin Framework 8 9d
- High CVE-2026-107588 Multiple Vulnerabilities in the Highcharts Library Bundled with Vaadin Charts 9d
- Medium CVE-2026-91860 Prototype Pollution in Vaadin Charts and Component Base via Unfiltered Deep Merge Sep 30, 2026
- Medium CVE-2026-93547 Missing Authorization Check in Vaadin Spreadsheet Allows Cell Comments to Be Written to Protected Sheets and Locked Cells Sep 30, 2026
- Low CVE-2026-7860 Possible information disclosure of environment variables in Vaadin Build Plugins via Failed Frontend Build May 19, 2026
- Medium CVE-2026-2742 Unauthorized session creation via reserved framework path access Mar 10, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-110737 is "Push Endpoint Returns Permissive CORS Headers", rated Low. It affects Flow (Vaadin); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.3 describes technical severity. EPSS 0.20% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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