High severity · published Mar 27, 2026
CVE-2026-5027
Langflow - Path Traversal Arbitrary File Write via upload_user_file
8.8
CVSS
40%
EPSS
No
On KEV
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 ('../').
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)40.0% · higher than 99% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LA
langflow · langflow-ai
0 · source: vendor, NVD
In the news
VulnerabilityHigh
Path traversal flaw in AI dev platform Langflow exploited in attacks
Attackers are actively exploiting CVE-2026-5027, a high-severity path traversal vulnerability in the AI development platform Langflow, to write arbitrary files on exposed servers. [...]
Jun 10, 2026·BleepingComputer
VulnerabilityHigh
Unpatched Langflow Flaw CVE-2026-5027 Exploited for Unauthenticated RCE
A high-severity unpatched security flaw in Langflow, an open-source low-code platform to build artificial intelligence (AI) applications, has come under active exploitation in the wild, according to findings from VulnCheck.
The vulnerability in question is CVE-2026-5027 (CVSS score: 8.8), a case of path traversal that could allow an attacker to write files to arbitrary locations.
"The 'POST /
Jun 10, 2026·The Hacker News
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5027
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5027
Vendor Advisory
https://www.tenable.com/security/research/tra-2026-26
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