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

published 2026-08-18 2 mo ago modified 2026-10-22 17 d ago also GHSA-34pm-923j-7wf8 , EUVD-2026-60976

cvss: 8.7; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 3

maven io.kestra:kestra 1.3.24

github.com/kestra-io/kestra@6c8e6d0 commit
github.com/kestra-io/kestra#16835 pull request
github.com/kestra-io/kestra/releases/tag/v1.3.24 release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 mo ago (2026-08-18)

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
GitHub	3.1	8.7	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	io.kestra:kestra	<1.3.24	1.3.24

Affected products

kestra-io kestra

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary