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Vulnerability record · CVE-2026-55839 · published 18 August 2026

CVE-2026-55839: Cross-site scripting vulnerability

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.

8.7 CVSS 3.1 High EPSS 0.43% · top 65.3% CWE-79 · Cross-site scripting Deferred
8.7CVSS 3.1 base score
0.43%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
4References
16 Sep 2026Last modified by NVD

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.

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

References

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

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Source: NIST National Vulnerability Database (record CVE-2026-55839), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.