Action captions in Vaadin accept HTML by default but were not sanitized, potentially allowing Cross-site Scripting (XSS) if caption content is derived from user input.
In Vaadin Framework 7 and 8, the Action class is a general-purpose class that may be used by multiple components. The fixed versions sanitize captions by default and provide an API to explicitly enable HTML content mode for backwards compatibility.
In Vaadin 23 and newer, the Action class is only used by the Spreadsheet component. The fixed versions sanitize HTML using Jsoup with a relaxed safelist.
Vaadin 14 is not affected as Spreadsheet component was not supported.
Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include:
Product version
Vaadin 7.0.0 - 7.7.49
Vaadin 8.0.0 - 8.29.1
Vaadin 23.1.0 - 23.6.5
Vaadin 24.0.0 - 24.8.13
Vaadin 24.9.0 - 24.9.6
Mitigation
Upgrade to 7.7.50
Upgrade to 8.30.0
Upgrade to 23.6.6
Upgrade to 24.8.14 or 24.9.7
Upgrade to 25.0.0 or newer
Artifacts Maven coordinatesVulnerable versionsFixed versioncom.vaadin:vaadin-server
7.0.0 - 7.7.49
≥7.7.50
com.vaadin:vaadin-server
8.0.0 - 8.29.1
≥8.30.0
com.vaadin:vaadin
23.1.0 - 23.6.5
≥23.6.6
com.vaadin:vaadin24.0.0 - 24.8.13
≥24.8.14
com.vaadin:vaadin24.9.0 - 24.9.6
≥24.9.7
com.vaadin:vaadin-spreadsheet-flow
23.1.0 - 23.6.5
≥23.6.6
com.vaadin:vaadin-spreadsheet-flow
24.0.0 - 24.8.13
≥24.8.14
com.vaadin:vaadin-spreadsheet-flow
24.9.0 - 24.9.6
≥24.9.7
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (4.8): severity, escalated by confirmed exploitation. This CVE's 4.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 4.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.3% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it