CVE-2026-104309: Langflow: path traversal exposes sensitive files

MEDIUM
Published October 29, 2026
CISO Take

IBM Langflow OSS 1.0.0 through 1.12.3 has a path traversal flaw (CWE-22) that lets any authenticated user read files outside the intended directory, with high confidentiality impact and no effect on integrity or availability. Exploitation is low complexity over the network, but it requires a valid account. There is no KEV listing, no public exploit, no Nuclei template and no EPSS data yet, so near-term exploitation likelihood looks low. Langflow servers usually hold LLM API keys, database credentials and flow definitions, so a file read can turn into wider compromise. Upgrade to the fixed release in the IBM advisory (node/7293015), limit Langflow accounts to people who need them, and keep the service off the public internet.

Sources:NVDibm.comATLAS

What is the risk?

Medium (CVSS 6.5). The attack is network-reachable, low complexity and needs no user interaction, but it requires low-privilege authentication. The impact is confidentiality only. There is no known exploitation, public PoC or scanner template, and EPSS is unavailable. The practical risk depends on exposure: shared or multi-tenant Langflow instances, and instances where self-registration is enabled, carry the highest risk. In an AI environment the files on the host are often high value, such as .env files with provider API keys, database credentials and saved flows.

How does the attack unfold?

Initial Access
The attacker authenticates to a Langflow instance with a low-privilege account.
AML.T0012
Exploitation
The attacker sends crafted requests with traversal sequences to escape the restricted directory.
AML.T0049
Collection
The attacker reads sensitive host files such as .env files, configuration databases and flow definitions.
AML.T0037
Impact
The attacker uses the exposed API keys and credentials to access LLM providers and connected data stores.
AML.T0055

What systems are affected?

PackageEcosystemVulnerable RangePatched
Langflowpip—No patch
156.0KPushed 6d ago18% patched~66d to patchFull package profile →

Do you use Langflow? You're affected.

How severe is it?

CVSS 3.1
6.5 / 10
EPSS
0.6%
chance of exploitation in 30 days
Higher than 49% of all CVEs
Exploitation Status
No known exploitation
Sophistication
Trivial

What is the attack surface?

AVACPRUISCIA
AVNetwork
ACLow
PRLow
UINone
SUnchanged
CHigh
INone
ANone

What should I do?

1 step
  1. 1) Upgrade Langflow OSS to the fixed version listed in IBM's advisory (https://www.ibm.com/support/pages/node/7293015). 2) Until patched, restrict access to trusted users, disable open registration, and place the service behind a VPN or SSO-enforcing reverse proxy. 3) Run Langflow as a low-privilege user in a container with a minimal filesystem and no host mounts of sensitive paths. 4) Rotate API keys and credentials stored on any instance that may have been exposed. 5) Detect: alert on requests with ../, encoded traversal sequences (%2e%2e%2f) or absolute paths in file-related API endpoints, and review access logs for unusual authenticated file reads. 6) Keep secrets in a secrets manager instead of local .env files.

How is it classified?

Which compliance frameworks are affected?

This CVE is relevant to:

EU AI Act
Art. 15-Accuracy, robustness and cybersecurity
ISO 42001
A.6.2.6-AI system operation and monitoring
NIST AI RMF
MANAGE 2.3-Respond to previously unknown risks
OWASP LLM Top 10
LLM02-Sensitive Information DisclosureLLM03-Supply Chain

Frequently Asked Questions

What is CVE-2026-104309?

IBM Langflow OSS 1.0.0 through 1.12.3 has a path traversal flaw (CWE-22) that lets any authenticated user read files outside the intended directory, with high confidentiality impact and no effect on integrity or availability. Exploitation is low complexity over the network, but it requires a valid account. There is no KEV listing, no public exploit, no Nuclei template and no EPSS data yet, so near-term exploitation likelihood looks low. Langflow servers usually hold LLM API keys, database credentials and flow definitions, so a file read can turn into wider compromise. Upgrade to the fixed release in the IBM advisory (node/7293015), limit Langflow accounts to people who need them, and keep the service off the public internet.

Is CVE-2026-104309 actively exploited?

No confirmed active exploitation of CVE-2026-104309 has been reported, but organizations should still patch proactively.

How to fix CVE-2026-104309?

1) Upgrade Langflow OSS to the fixed version listed in IBM's advisory (https://www.ibm.com/support/pages/node/7293015). 2) Until patched, restrict access to trusted users, disable open registration, and place the service behind a VPN or SSO-enforcing reverse proxy. 3) Run Langflow as a low-privilege user in a container with a minimal filesystem and no host mounts of sensitive paths. 4) Rotate API keys and credentials stored on any instance that may have been exposed. 5) Detect: alert on requests with ../, encoded traversal sequences (%2e%2e%2f) or absolute paths in file-related API endpoints, and review access logs for unusual authenticated file reads. 6) Keep secrets in a secrets manager instead of local .env files.

What systems are affected by CVE-2026-104309?

This vulnerability affects the following AI/ML architecture patterns: agent frameworks, RAG pipelines, LLM workflow orchestration, low-code AI application builders.

What is the CVSS score for CVE-2026-104309?

CVE-2026-104309 has a CVSS v3.1 base score of 6.5 (MEDIUM). The EPSS exploitation probability is 0.60%.

What is the AI security impact?

Affected AI Architectures

agent frameworksRAG pipelinesLLM workflow orchestrationlow-code AI application builders

MITRE ATLAS Techniques

AML.T0037Data from Local System
AML.T0049Exploit Public-Facing Application
AML.T0055Unsecured Credentials

Compliance Controls Affected

EU AI Act: Art. 15
ISO 42001: A.6.2.6
NIST AI RMF: MANAGE 2.3
OWASP LLM Top 10: LLM02, LLM03

What are the technical details?

Original Advisory

IBM Langflow OSS 1.0.0 through 1.12.3 could allow a remote authenticated attacker to obtain sensitive information due to improper limitation of a pathname to a restricted directory.

Exploitation Scenario

An attacker obtains low-privilege Langflow credentials, for example through a shared team account, leaked credentials or open sign-up. They send crafted requests to a file-handling endpoint using ../ sequences to escape the permitted directory. They read the .env file, the configuration database and saved flows, and recover LLM provider API keys and vector database credentials. They then use those keys to run inference at the victim's expense and to access the data in connected stores.

Weaknesses (CWE)

CWE-22 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'): The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

  • [Implementation] Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylis
  • [Architecture and Design] For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Source: MITRE CWE corpus.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Timeline

Published
October 29, 2026
Last Modified
October 30, 2026
First Seen
October 29, 2026

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