Langflow - Path Traversal Arbitrary File Write via upload_user_file

published 2026-03-27 7mo ago modified 2026-08-18 2mo ago also EUVD-2026-16668

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 40.0%; EPSS 40.0% chance of exploitation in 30 days, percentile 98%
public exploits: 1; Exploit-DB

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 ('../').

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Timeline

2026-03-27 Published
2026-08-31 First public exploit (EDB-52659)

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 7mo ago (2026-03-27)

Exploit prediction

39.97% chance of exploitation in the next 30 days, higher than 98% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

EDB-52659 Langflow 1.8.4 - Path Traversal to Remote Code Execution webapps, 2026-08-31

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

langflow-ai langflow

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

tenable.com /security/research/tra-2026-26
vendor-advisory, third-party-advisory

Sources

CVE List CVE-2026-5027
NVD CVE-2026-5027

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

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