High 8.7Published Aug 18, 2026

CVE-2026-55839Kestra: Stored XSS via custom Markdown [[link]] attribute injection

Updated under an hour ago (2026-10-19 11:20 UTC)

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It affects kestra-io kestra. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 8.7 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Weakness (CWE): CWE-79
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Aug 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

kestra-io kestra kestra_io:kestra (from the name)	before 1.3.24	CNA record

References

https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8x-refsource-confirm
https://github.com/kestra-io/kestra/pull/16835x-refsource-misc
https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710ex-refsource-misc
https://github.com/kestra-io/kestra/releases/tag/v1.3.24x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.