What is the CVSS score of CVE-2026-33664?

CVE-2026-33664 has a CVSS 3.1 base score of 7.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Which versions of Kestra are affected by CVE-2026-33664?

Kestra orchestration platform versions up to 1.3.3 contain a stored cross-site scripting vulnerability that allows authenticated flow authors to embed malicious code in flow metadata, which executes…

How to fix or mitigate CVE-2026-33664?

Within 24 hours: Inventory all Kestra deployments and confirm versions affected (up to 1.3.3); restrict access to flow creation/editing to trusted authors only and disable flow sharing with lower-privileged users. Within 7 days: Monitor Kestra advisory channels and vendor GitHub for patch release confirmation; test any released patches in a non-production environment. Within 30 days: Apply patched version immediately upon vendor release confirmation; audit recent flow creation activity for suspicious metadata in description and displayName fields.

Kestra CVE-2026-33664

EUVD-2026-16430 HIGH

Cross-site Scripting (XSS) (CWE-79)

2026-03-26 GitHub_M

XSS Kestra Kestra Io

7.3

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

7.3 HIGH

AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

EUVD ID Assigned

Mar 26, 2026 - 21:31 euvd

EUVD-2026-16430

Analysis Generated

Mar 26, 2026 - 21:31 vuln.today

CVE Published

Mar 26, 2026 - 21:13 nvd

HIGH 7.3

DescriptionGitHub Advisory

Kestra is an open-source, event-driven orchestration platform Versions up to and including 1.3.3 render user-supplied flow YAML metadata fields - description, inputs[].displayName, inputs[].description - through the Markdown.vue component instantiated with html: true. The resulting HTML is injected into the DOM via Vue's v-html without any sanitization. This allows a flow author to embed arbitrary JavaScript that executes in the browser of any user who views or interacts with the flow. This is distinct from GHSA-r36c-83hm-pc8j / CVE-2026-29082, which covers only FilePreview.vue rendering .md files from execution outputs. The present finding affects different components, different data sources, and requires significantly less user interaction (zero-click for input.displayName). As of time of publication, it is unclear if a patch is available.

AnalysisAI

Cross-site scripting in Kestra orchestration platform versions up to 1.3.3 enables authenticated flow authors to inject arbitrary JavaScript through unsanitized Markdown rendering in flow metadata fields (description, input displayName/description). The malicious scripts execute automatically when other users view the flow in the web UI, requiring zero interaction for input.displayName fields. This vulnerability (CVSS 7.3) differs from CVE-2026-29082 and affects different components with lower interaction requirements. No public exploit identified at time of analysis, and patch availability remains unconfirmed per the advisory.

Technical ContextAI

Kestra is an event-driven workflow orchestration platform (cpe:2.3:a:kestra-io:kestra). The vulnerability stems from CWE-79 (Improper Neutralization of Input During Web Page Generation) in the Markdown.vue component. Flow YAML metadata fields are rendered with the html:true configuration option and injected into the Document Object Model via Vue.js v-html directive without sanitization. This architectural decision allows HTML pass-through in user-controlled content, creating stored XSS attack vectors. The affected fields include flow descriptions and input metadata properties that are displayed in the Kestra web interface during normal workflow viewing and interaction workflows.

RemediationAI

As of time of publication, patch availability for this vulnerability is unclear according to the source advisory at https://github.com/kestra-io/kestra/security/advisories/GHSA-v2mc-8q95-g7hp. Organizations should monitor the Kestra security advisories and GitHub repository for updates. Until a confirmed patch is released and deployed, implement defense-in-depth controls: restrict flow authorship permissions to trusted administrators only, implement Content Security Policy headers to mitigate script execution, enable audit logging for flow modifications, and consider input validation at the application gateway layer. Review existing flows for suspicious content in description and input metadata fields. Subscribe to the GitHub advisory for patch notifications.