CVE-2026-91860

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.46% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 40.1% of scored records. A rank, not a probability.

NVD base score

6.3 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

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

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-09-30.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-30 13:13Z28 DAYS AGO

Last updated

2026-09-30 14:26Z28 DAYS AGO

Reserved

2026-09-15

Assigning CNA

Vaadin

Record state

PUBLISHED

Severity

Medium (CVSS 6.3)

CNA CVSS vector

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

Weaknesses

• CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')Variant

Data version

5.2

Document digest

81686659f899aabec1b5e49c779340567dfbf20959c481323d0481117f141dba

• vaadin.comhttps://vaadin.com/security/cve-2026-91860
• github.comhttps://github.com/vaadin/web-components/pull/12483
• github.comhttps://github.com/vaadin/web-components/pull/12492
• github.comhttps://github.com/vaadin/web-components/pull/12493
• github.comhttps://github.com/vaadin/web-components/pull/12494
• github.comhttps://github.com/vaadin/web-components/pull/12496
• github.comhttps://github.com/vaadin/web-components/pull/12559