CVE-2026-5027

Langflow - Path Traversal Arbitrary File Write via upload_user_file

At a glance

Severity: HIGH 8.8
EPSS: EPSS 39.97 % · percentile 99 (2026-10-27)
State: PUBLISHED
Published: 2026-03-27
Updated: 2026-03-27
Assigner: tenable
NVD status: Analyzed

Description

The 'POST /api/v2/files' endpoint does not sanitize the 'filename' parameter from the multipart form data, allowing an attacker to write files to arbitrary locations on the filesystem using path traversal sequences ('../').

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	tenable
CVSS 3.1	HIGH 8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	NVD · vulnreport@tenable.com (Secondary)

Weaknesses (CWE)

CWE-22

European references

ENISA EUVD · EUVD-2026-16668
GCVE · GCVE-0-2026-5027

Affected configurations (NVD CPE)

cpe:2.3:a:langflow:langflow:*:-:*:*:*:*:*:* < 1.9.0

Affected products

Product	Versions
langflow-ai · langflow	affected 0

References

https://www.tenable.com/security/research/tra-2026-26

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD