CVE-2026-55839

HIGH
MEDIUM Priority: 0.04 BB Relevance: 57/100
Published: 2026-08-18 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity Conf. Impact Integ. Impact Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: Required
S: Changed
C: High
I: High
A: None

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.

Weakness Classification (1)

Bug Bounty Relevance

57 / 100
✓ Network accessible
✓ Low complexity

CVSS Score

8.7 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS — Exploitation Probability

0.43%
Raw Score 0.004300
Percentile 37.2%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00430
2026-10-28
0.00430

Intelligence Sources

nvd ref →