CVE-2026-5026 Langflow - Stored XSS via Malicious SVG Upload

What is CVE-2026-5026?

CVE-2026-5026 is a high-severity cross-site scripting vulnerability in Langflow Langflow, published on 27 Mar 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-79

Which versions are affected by CVE-2026-5026?

It affects 1 product.

Products include Langflow Langflow.

How do I fix CVE-2026-5026?

No fix has been published for CVE-2026-5026 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-5026 being exploited?

There is no known exploitation of CVE-2026-5026 in the wild and no public exploit code.

Other vulnerabilities in Langflow Langflow

• CVE-2026-9198 IBM Langflow Code Injection Exploited Critical 9.8
• CVE-2026-0770 Langflow Inclusion of Functionality from Untrusted Control Sphere Exploited Critical 9.8
• CVE-2025-3248 Langflow Missing Authentication Exploited Critical 9.8
• CVE-2025-34291 Langflow Origin Validation Error Exploited Critical 9.4
• CVE-2026-33017 Langflow Code Injection Exploited Critical 9.3

All Langflow Langflow vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-89f7-r7x8-83q7.