Medium severity · published Mar 26, 2026
CVE-2026-33664
Kestra Vulnerable to Stored Cross-Site Scripting via Flow YAML Fields
5.4
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
kestra · kestra-io
<= 1.3.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33664
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33664
Exploit
https://github.com/kestra-io/kestra/security/advisories/GHSA-v2mc-8q95-g7hp
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