CVE-2026-55839Kestra: Stored XSS via custom Markdown [[link]] attribute injection
- 8.7HighCVSS base score
- 0.43%Exploitation in 30 daysEPSS · top 62% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 2 months later
· 2 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
| NVDNVD · Deferred | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.43% · top 62% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Mavenio.kestra:kestraGHSA-34pm-923j-7wf8 (opens in a new tab)
References
References4
- https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/kestra-io/kestra/pull/16835 (opens in a new tab)x_refsource_MISC
- https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e (opens in a new tab)x_refsource_MISC
- https://github.com/kestra-io/kestra/releases/tag/v1.3.24 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-60976 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-34pm-923j-7wf8 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55839)Record last updated .