CVE-2026-42138: Dify Vulnerable to Stored XSS via SVG-file upload

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-05-04 · updated 2026-10-26
Weakness: CWE-79

Description

Dify is an open-source LLM app development platform. Prior to version 1.13.1, using the method POST /api/files/upload, any unauthenticated user can upload an SVG file with XSS. The method POST /v1/files/upload, which requires authentication through the application API, is also vulnerable. This issue has been patched in version 1.13.1.

Affected products

langgenius dify: before 1.13.1 — fixed in 1.13.1

How to fix

Upgrade to a fixed version: langgenius dify 1.13.1. Check the vendor advisory for mitigations.

References

https://github.com/langgenius/dify/releases/tag/1.13.1
https://github.com/langgenius/dify/security/advisories/GHSA-cg94-8v83-7hjj
https://github.com/langgenius/dify/security/advisories/GHSA-cg94-8v83-7hjj

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