CVE-2026-55839

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

Description

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.

Scores

Weaknesses (CWE)

• CWE-79

Advisories

• GHSA-34pm-923j-7wf8 — Kestra vulnerable to stored XSS via custom Markdown [[link]] attribute injection

European references

• ENISA EUVD · EUVD-2026-60976
• GCVE · GCVE-0-2026-55839

Affected products

References

• https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8
• https://github.com/kestra-io/kestra/pull/16835
• https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e
• https://github.com/kestra-io/kestra/releases/tag/v1.3.24

Sources