CVE-2026-55839: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in kestra-io kestra
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.
AI Analysis
Technical Summary
CVE-2026-55839 is a stored cross-site scripting vulnerability in Kestra's custom Markdown parser located in ui/src/utils/markdown_plugins/link.ts. Specifically, users with permission to create or update Flow descriptions can inject JavaScript event-handler attributes through the custom [[link]] syntax. When another user views the affected description or information panel in the Flow list, the malicious script executes, leading to stored XSS. This vulnerability affects Kestra versions prior to 1.3.24 and is resolved in version 1.3.24.
Potential Impact
Successful exploitation allows an attacker with limited privileges (permission to create or update Flow descriptions) to execute arbitrary JavaScript in the context of other users viewing the Flow description or information panel. This can lead to full compromise of user session confidentiality and integrity (high confidentiality and integrity impact), but does not affect availability.
Mitigation Recommendations
Upgrade Kestra to version 1.3.24 or later, where this vulnerability is fixed. No other official remediation or temporary fixes are documented. Until upgrading, restrict permissions to create or update Flow descriptions to trusted users only.
CVE-2026-55839: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in kestra-io kestra
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 v3.1
Score 8.7high
Affected software
kestra-io
kestra
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-55839 is a stored cross-site scripting vulnerability in Kestra's custom Markdown parser located in ui/src/utils/markdown_plugins/link.ts. Specifically, users with permission to create or update Flow descriptions can inject JavaScript event-handler attributes through the custom [[link]] syntax. When another user views the affected description or information panel in the Flow list, the malicious script executes, leading to stored XSS. This vulnerability affects Kestra versions prior to 1.3.24 and is resolved in version 1.3.24.
Potential Impact
Successful exploitation allows an attacker with limited privileges (permission to create or update Flow descriptions) to execute arbitrary JavaScript in the context of other users viewing the Flow description or information panel. This can lead to full compromise of user session confidentiality and integrity (high confidentiality and integrity impact), but does not affect availability.
Mitigation Recommendations
Upgrade Kestra to version 1.3.24 or later, where this vulnerability is fixed. No other official remediation or temporary fixes are documented. Until upgrading, restrict permissions to create or update Flow descriptions to trusted users only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-17T16:29:38.865Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a847f32c6e8be03326a99a9
Added to database: 08/18/2026, 15:50:10 UTC
Last enriched: 08/18/2026, 16:04:26 UTC
Last updated: 10/02/2026, 10:15:00 UTC
Views: 73
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