Vulnerability · Published Mar 27, 2026 · Assigned by tenable

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

High 7.0

In plain English

A high-severity cross-site scripting in langflow from langflow-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).

Severity (CVSS 4.0)7.0High

Exploit odds (30 days)0.2%top 94.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
langflow-ai	langflow	0

Weakness: CWE-79 · 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

References

https://www.tenable.com/security/research/tra-2026-25