CVE Intelligence
Medium Injection

CVE-2026-91860 — Prototype Pollution in Vaadin Charts and Component Base via Unfiltered Deep Merge

A prototype pollution vulnerability exists in the deep merge helpers of Vaadin Charts and Vaadin Component Base. Merging an object the application does not control into a chart configuration or into a component's i18n property writes onto Object.prototype, making the injected properties visible to every object in the running application. Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include: Product version Vaadin 23.0.0 - 23.6.13 Vaadin 24.0.0 - 24.9.20 Vaadin 24.10.0 - 24.10.9 Vaadin 25.0.0 - 25.1.11 Vaadin 25.2.0 - 25.2.6 Mitigation Upgrade to 23.6.14 Upgrade to 24.9.21 Upgrade to 24.10.10 Upgrade to 25.1.12 Upgrade to 25.2.7 or newer Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 23, 24, 25 version. Artifacts Maven coordinates Vulnerable versions Fixed version com.vaadin:vaadin 23.0.0 - 23.6.13 >=23.6.14 com.vaadin:vaadin 24.0.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin 25.2.0 - 25.2.6 >=25.2.7 com.vaadin:vaadin-core 24.7.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin-core 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin-core 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin-core 25.2.0 - 25.2.6 >=25.2.7 com.vaadin:vaadin-charts-flow 23.0.0 - 23.6.13 >=23.6.14 com.vaadin:vaadin-charts-flow 24.0.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin-charts-flow 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin-charts-flow 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin-charts-flow 25.2.0 - 25.2.6 >=25.2.7 npm packages npm package Vulnerable versions Fixed version @vaadin/charts 23.0.0 - 23.6.4 >=23.6.5 @vaadin/charts 24.0.0 - 24.9.17 >=24.9.18 @vaadin/charts 24.10.0 - 24.10.4 >=24.10.5 @vaadin/charts 25.0.0 - 25.1.11 >=25.1.12 @vaadin/charts 25.2.0 - 25.2.8 >=25.2.9 @vaadin/component-base 24.7.0 - 24.9.17 >=24.9.18 @vaadin/component-base 24.10.0 - 24.10.4 >=24.10.5 @vaadin/component-base 25.0.0 - 25.1.11 >=25.1.12 @vaadin/component-base 25.2.0 - 25.2.8 >=25.2.9

Published Sep 30, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Vaadin

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.5% (30-day exploitation probability)+6
  • Technical severity (medium)+3

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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.47%
ahead of 39% of scored CVEs · Oct 15, 2026
Affects
Vaadin
@vaadin/charts and 4 more
CVSS base
6.3
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Vaadin @vaadin/charts, Vaadin @vaadin/component-base, Vaadin Vaadin…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Vaadin @vaadin/charts ≥ 25.2.0 and < 25.2.9≥ 25.0.0 and < 25.1.12≥ 24.10.0 and < 24.10.5≥ 24.0.0 and < 24.9.18≥ 23.0.0 and < 23.6.5 Vulnerable CVE Program (cve.org) e CISA ADP
Vaadin @vaadin/component-base ≥ 25.2.0 and < 25.2.9≥ 25.0.0 and < 25.1.12≥ 24.10.0 and < 24.10.5≥ 24.7.0 and < 24.9.18 Vulnerable CVE Program (cve.org) e CISA ADP
Vaadin Vaadin ≥ 24.0.0 and < 24.9.21≥ 25.2.0 and < 25.2.7≥ 25.0.0 and < 25.1.12≥ 24.10.0 and < 24.10.10≥ 23.0.0 and < 23.6.14 Vulnerable CVE Program (cve.org) e CISA ADP
Vaadin Vaadin-charts-flow ≥ 24.0.0 and < 24.9.21≥ 24.10.0 and < 24.10.10≥ 25.0.0 and < 25.1.12≥ 25.2.0 and < 25.2.7≥ 23.0.0 and < 23.6.14 Vulnerable CVE Program (cve.org) e CISA ADP
Vaadin Vaadin-core ≥ 25.2.0 and < 25.2.7≥ 25.0.0 and < 25.1.12≥ 24.10.0 and < 24.10.10≥ 24.7.0 and < 24.9.21 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
None
Scope
X
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
Low
Availability (vulnerable system)
Low
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.3 CVSS 4.0 Medium — — security@vaadin.com via NIST National Vulnerability Database
6.3 CVSS 4.0 Medium — — Vaadin via CVE Program (cve.org) e CISA ADP
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/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.

CWE-1321 · Prototype Pollution

Other CVEs with this weakness →

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).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · vaadin/vaadin, vaadin/vaadin-core, vaadin/vaadin-charts-flow, vaadin/@vaadin/charts, vaadin/@vaadin/component-base
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 6.3
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 30, 2026 · Vaadin

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

7 on the record

Elsewhere on this site

Vaadin
every CVE for this vendor
Injection
same class
CWE-1321
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-93547 Missing Authorization Check in Vaadin Spreadsheet Allows Cell Comments to Be Written to Protected Sheets and Locked Cells 16d
  • CVE-2026-2742 Unauthorized session creation via reserved framework path access Mar 10, 2026
  • CVE-2026-2741 Zip Slip Path Traversal on Node Unpack Mar 10, 2026
  • CVE-2025-15022 Cross-site scripting in Action caption Jan 5, 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 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-2026-91860 is "Prototype Pollution in Vaadin Charts and Component Base via Unfiltered Deep Merge", rated Medium. It affects @vaadin/charts (Vaadin); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.3 describes technical severity. EPSS 0.47% 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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