CVE-2026-5026 PUBLISHED

Langflow - Stored XSS via Malicious SVG Upload

Assigner: tenable
Reserved: 27.03.2026 Published: 27.03.2026 Updated: 27.03.2026

The '/api/v1/files/images/{flow_id}/{file_name}' endpoint serves SVG files with the 'image/svg+xml' content type without sanitizing their content.

Since SVG files can contain embedded JavaScript, an attacker can upload a malicious SVG that executes arbitrary JavaScript when viewed by other users, leading to stored cross-site scripting (XSS). This allows stealing authentication tokens stored in cookies, including JWT access and refresh tokens.

Metrics

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 7

Product Status

Vendor langflow-ai
Product langflow
Versions Default: unaffected
  • Version 0 is affected

References

Problem Types

  • CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') CWE