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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-55839
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-18 16:17:53 UTC
Updated2026-08-18 18:18:32 UTC
DescriptionKestra 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.

Risk And Classification

Primary CVSS: v3.1 8.7 HIGH from [email protected]

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

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

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.7HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
3.1CNADECLARED8.7HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Kestra-io Kestra affected < 1.3.24 Not specified

References

ReferenceSourceLinkTags
github.com/kestra-io/kestra/pull/16835 [email protected] github.com
github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8 [email protected] github.com
github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e [email protected] github.com
github.com/kestra-io/kestra/releases/tag/v1.3.24 [email protected] github.com
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