{"id":"CVE-2026-55839","state":"PUBLISHED","title":"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.","publishedAt":"2026-08-18T15:27:18.261Z","updatedAt":"2026-08-18T17:46:37.126Z","severity":{"score":8.7,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["kestra-io kestra"],"affected":[{"vendor":"kestra-io","product":"kestra","versions":[{"version":"< 1.3.24","status":"affected"}]}],"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"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/55xxx/CVE-2026-55839.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55839","state":"PUBLISHED","datePublished":"2026-08-18T15:27:18.261Z","dateUpdated":"2026-08-18T17:46:37.126Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-17T16:29:38.865Z"},"containers":{"cna":{"title":"Kestra: Stored XSS via custom Markdown [[link]] attribute injection","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"kestra-io","product":"kestra","versions":[{"version":"< 1.3.24","status":"affected"}]}],"references":[{"url":"https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8","name":"https://github.com/kestra-io/kestra/security/advisories/GHSA-34pm-923j-7wf8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/kestra-io/kestra/pull/16835","name":"https://github.com/kestra-io/kestra/pull/16835","tags":["x_refsource_MISC"]},{"url":"https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e","name":"https://github.com/kestra-io/kestra/commit/6c8e6d099ed172cbb6b003b7fb30b7bb1f8f710e","tags":["x_refsource_MISC"]},{"url":"https://github.com/kestra-io/kestra/releases/tag/v1.3.24","name":"https://github.com/kestra-io/kestra/releases/tag/v1.3.24","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-18T15:27:18.261Z"},"source":{"advisory":"GHSA-34pm-923j-7wf8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-18T17:28:28.962947Z","id":"CVE-2026-55839","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-18T17:46:37.126Z"}}]}}}