Answer in brief
CVE-2026-120326 records a Medium severity (CVSS 4.8) vulnerability in Unescaped Download File Name Allows Content-Disposition Parameter Injection in Vaadin Flow. The current sources do not mark it as known exploited. The current feed maps vaadin/com.vaadin:flow-server (generic), vaadin/com.vaadin:vaadin (generic), vaadin/com.vaadin:vaadin-core (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps vaadin/com.vaadin:flow-server (generic), vaadin/com.vaadin:vaadin (generic), vaadin/com.vaadin:vaadin-core (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| vaadin/com.vaadin:flow-servergeneric | >=24.8.0 <=24.8.16 || >=24.9.0 <24.9.31 || >=24.10.0 <24.10.17 || >=25.0.0 <=25.0.15 || >=25.1.0 <=25.1.19 || >=25.2.0 <25.2.16 || >=25.3.0 <25.3.6 | 24.9.31, 24.10.17, 25.2.16, 25.3.6 |
| vaadin/com.vaadin:vaadingeneric | >=24.8.0 <=24.8.17 || >=24.9.0 <24.9.26 || >=24.10.0 <24.10.14 || >=25.0.0 <=25.0.13 || >=25.1.0 <=25.1.13 || >=25.2.0 <25.2.13 || >=25.3.0 <25.3.5 | 24.9.26, 24.10.14, 25.2.13, 25.3.5 |
| vaadin/com.vaadin:vaadin-coregeneric | >=24.8.0 <=24.8.17 || >=24.9.0 <24.9.26 || >=24.10.0 <24.10.14 || >=25.0.0 <=25.0.13 || >=25.1.0 <=25.1.13 || >=25.2.0 <25.2.13 || >=25.3.0 <25.3.5 | 24.9.26, 24.10.14, 25.2.13, 25.3.5 |
Published upstream
Nov 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 10, 2026
DownloadEvent.setFileName(String) in Vaadin Flow writes the download file name into the Content-Disposition header without escaping it. When the name is pure US-ASCII the header is built as attachment; filename="<name>" with the name inserted verbatim, so a double quote in the name ends the quoted string early and the rest of the name is read by the browser as further header parameters. The inline(String) variant, present from Vaadin 25.0, builds the name the same way. An application that passes an untrusted file name to either method, for example when re-serving a file under the name it was uploaded with, lets an attacker add a filename* parameter. Browsers prefer filename* over filename, so the file is saved under a name and extension of the attacker's choosing, which defeats any file name or extension restriction the application enforces. The attacker cannot change the attachment or inline disposition itself and cannot split the header. Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include: Product version Vaadin 24.8.0 - 24.8.17 Vaadin 24.9.0 - 24.9.25 Vaadin 24.10.0 - 24.10.13 Vaadin 25.0.0 - 25.0.13 Vaadin 25.1.0 - 25.1.13 Vaadin 25.2.0 - 25.2.12 Vaadin 25.3.0 - 25.3.4 Mitigation No fixed release on this line, upgrade to 24.9.26 or newer Upgrade to 24.9.26 Upgrade to 24.10.14 No fixed release on this line, upgrade to 25.2.13 or newer No fixed release on this line, upgrade to 25.2.13 or newer Upgrade to 25.2.13 Upgrade to 25.3.5 Vaadin versions below 24.8 are not affected: the DownloadEvent API does not exist in them.
Quoted source text, attributed separately from HOL analysis.