Security Bulletin
Summary
Langflow contains multiple authenticated path-traversal vulnerabilities that allow an attacker to read arbitrary files accessible to the Langflow server process, bypassing the LANGFLOW_RESTRICT_LOCAL_FILE_ACCESS=true security control. The ChatInput component's files parameter accepts absolute paths through the authenticated flow-build API; these are resolved via Python pathlib join semantics that reset the path on an absolute segment, and the resulting path is read by the message attachment pipeline without calling the local-file access guard. Bundle components such as JigsawStack File Upload resolve a FileInput path through the full path builder without the access guard, then open the file with a raw file open call, allowing file bytes to be exfiltrated to an attacker-controlled storage endpoint. The GitExtractor component validates the repository URL to block local clones but does not inspect the cloned tree for symbolic links; an attacker-controlled remote repository containing absolute-path symlinks causes the file-walk logic to follow those symlinks and return out-of-tree server file contents in the flow output. High-value targets include application secret keys, JWT signing keys, OS credential files, and environment variables accessible to the service identity.
Vulnerability Details
CVEID: CVE-2026-19306
DESCRIPTION: Langflow OSS allows an authenticated attacker to read arbitrary files from the server filesystem — including server secret material (secret_key, JWT signing keys, the application database, /proc/self/environ, and other tenants' upload directories) — by supplying absolute paths or traversal sequences in the files parameter of an authenticated build request. The file contents were embedded as text attachments in the language model prompt and transmitted to the configured model endpoint, resulting in confidential data exfiltration. This bypassed the LANGFLOW_RESTRICT_LOCAL_FILE_ACCESS=true containment boundary, which was enforced for other file-reading components but not for the Chat Input to Message attachment pipeline.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: IBM
CVSS Base score: 7.7
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N)
CVEID: CVE-2026-19299
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to obtain sensitive information due to path traversal.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: IBM
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
CVEID: CVE-2026-19302
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to obtain sensitive information due to improper validation of symbolic links.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: IBM
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Langflow OSS | 1.0.0-1.11.2 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.3
Workarounds and Mitigations
None
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References
Acknowledgement
Change History
28 Aug 2026: Initial Publication
*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.
Disclaimer
According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.
Document Location
Worldwide
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Document Information
Modified date:
28 August 2026
Initial Publish date:
28 August 2026
UID
ibm17285641