CVE-2026-55839 PUBLISHED

Kestra: Stored XSS via custom Markdown [[link]] attribute injection

Assigner: GitHub_M
Reserved: 17.06.2026 Published: 18.08.2026 Updated: 18.08.2026

Kestra is an open-source, event-driven orchestration platform. Prior to 1.3.24, Kestra's custom Markdown parser in ui/src/utils/markdown_plugins/link.ts allows a user with permission to create or update a Flow description to inject JavaScript event-handler attributes through the custom [[link]] syntax, causing stored cross-site scripting when another user opens the description or information panel in the Flow list. This issue is fixed in version 1.3.24.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CVSS Score: 8.7

Product Status

Vendor kestra-io
Product kestra
Versions
  • Version < 1.3.24 is affected

References

Problem Types

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE