Application-wide prototype pollution via unsafe deep merge
Published Sep 30, 2026 · Updated Sep 30, 2026
Prototype pollution in Vaadin Charts and Component Base allows context-dependent attackers to alter inherited object properties via unsafe merges. Their deep merge helpers copy application-uncontrolled chart configuration or component i18n keys onto Object.prototype, making injected properties visible throughout the running application. Exploitation requires an application to pass attacker-influenced objects into one of those merge paths; any further security consequence depends on how that application uses inherited properties.
Summary
What happened
Prototype pollution in Vaadin Charts and Component Base allows context-dependent attackers to alter inherited object properties via unsafe merges. Their deep merge helpers copy application-uncontrolled chart configuration or component i18n keys onto Object.prototype, making injected properties visible throughout the running application. Exploitation requires an application to pass attacker-influenced objects into one of those merge paths; any further security consequence depends on how that application uses inherited properties.
The record
- CVE
- CVE-2026-91860
- Published
- Sep 30, 2026
- Updated
- Sep 30, 2026
- Vendor
- Vaadin
- Product
- Vaadin Core
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Sep 30, 2026CVE publishedPublication date reported by the CVE source.
- Sep 30, 2026Record 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.
- Affected versionversion=24.10.0 <24.10.10
- Affected versionversion=24.7.0 <24.9.21
- Affected versionversion=25.0.0 <25.1.12
- Affected versionversion=25.2.0 <25.2.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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