VulnCheck reports active exploitation of critical Langflow CVE-2026-0768 and Rails CVE-2026-66066 for credential harvesting, with detections rising to 360.
VulnCheck observed active exploitation of CVE-2026-0768 (CVSS 9.8) in Langflow and CVE-2026-66066 'KindaRails2Shell' (CVSS 9.5) in Ruby on Rails, with detections rising from 50 on August 30, 2026 to 360 by September 1. The Rails flaw allows unauthenticated arbitrary file reads, leaking secret_key_base, Rails master key, database passwords, cloud credentials and API tokens, ultimately enabling RCE; the patch still leaves the variation-key Marshal deserialization RCE gadget functional. Observed chains include a Python credential harvester with SimpleHelp remote access via CVE-2026-5027, and weaponization of CVE-2025-3248 to enlist hosts into an XMR mining botnet after disabling auditd. More than 7,100 exposed vulnerable Ruby on Rails instances and over 15,000 successful exploitation attempts across three Langflow flaws were recorded.
Unauthenticated RCE in Langflow /api/v1/validate/code
Langflow, an open-source visual framework for building LLM and agentic AI applications, contains a missing authentication flaw (CWE-306) in its /api/v1/validate/code endpoint. A remote attacker with network reachability to the endpoint can send crafted HTTP requests without any credentials, causing arbitrary code execution on the server. Successful exploitation yields code execution under the application's privileges, enabling data theft, backdoor installation, and, per CISA, ransomware deployment. Any running Langflow instance is affected; the tool is typically self-hosted by development teams building AI workflows, so real-world exposure depends on whether each instance is reachable from untrusted networks. Exploitation is confirmed in the wild: the flaw was added to CISA's KEV catalog on 2025-05-05 with known ransomware use, EPSS assigns a 100% probability of exploitation within 30 days (100th percentile), and a public PoC is available.
Unauthenticated Eval Injection RCE in Langflow (eval_custom_component_code)
CVE-2026-0769 is a critical (CVSS 9.8) unauthenticated remote code execution vulnerability in Langflow, an open-source platform for building LLM applications, located in the eval_custom_component_code function. The function fails to properly validate a user-supplied string before using it to execute Python code, so a remote attacker who can reach the Langflow service without any credentials can submit a crafted string that is then executed as Python code. Successful exploitation yields arbitrary code execution in the context of the current process, with full confidentiality, integrity, and availability impact on the affected host. Any Langflow deployment is potentially exposed, particularly self-hosted or internet-facing instances that accept unauthenticated API requests. Exploitation of critical Langflow flaws has been reported in the wild in recent credential-focused campaigns; this CVE itself is not yet in CISA KEV and has no known public PoC, but its EPSS of 38% (98th percentile) signals high near-term exploitation risk.
Langflow code Code Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Langflow. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of the code parameter provided to the validate endpoint. The issue results from the lack of proper validation of a user-supplied string before using it to execute Python code. An attacker can leverage this vulnerability to execute code in the context of root. . Was ZDI-CAN-27322.
Unauthenticated Arbitrary File Read in Ruby on Rails Active Storage
CVE-2026-66066 is a flaw in Active Storage (part of Ruby on Rails' Action Pack) in which libvips operations that are marked unsafe for untrusted content are not disabled, so a crafted upload can invoke such an operation on the server. It is triggered when an unauthenticated attacker uploads a maliciously crafted image to a Rails application that is configured to use libvips and accepts image uploads from untrusted users. Successful exploitation lets the attacker read arbitrary files accessible to the Rails process, including environment variables and application secrets; leaked credentials such as secret_key_base or external-service tokens can be leveraged for remote code execution or lateral movement. Affected applications are those running Rails 7.2.x, 8.0.x or 8.1.x before the patched releases 7.2.3.2, 8.0.5.1 and 8.1.3.1, provided Active Storage with libvips is in use. Public exploit code is not yet documented, but news reports describe active attacks against Rails apps (a campaign referred to as "KindaRails2Shell"), EPSS assigns a 27.9% probability of exploitation within 30 days (98th percentile), and the flaw is not yet listed in CISA KEV.
· Ruby on Rails Active Storage (Action Pack) 7.2.x prior to 7.2.3.2 · Ruby on Rails Active Storage (Action Pack) 8.0.x prior to 8.0.5.1mass
Authenticated Path Traversal Arbitrary File Write in Langflow Files API
CVE-2026-5027 is a path traversal flaw (CWE-22) in the 'POST /api/v2/files' endpoint of Langflow, the open-source platform for building AI/LLM agent workflows. The endpoint fails to sanitize the 'filename' field supplied in multipart form data, so an attacker who submits a name containing '../' sequences can direct the resulting file write to arbitrary locations on the server's filesystem. The CVSS vector (network-accessible, low complexity, low-privilege account required, no user interaction) indicates an authenticated user can abuse this to overwrite or create files at attacker-chosen paths, which can compromise confidentiality, integrity, and availability — for example by overwriting configuration, credentials, or executable content that leads to code execution depending on deployment. Any organization running a self-hosted Langflow instance that exposes the files API, even to low-privileged accounts, is affected. No public proof-of-concept or confirmed in-the-wild exploitation is known for this specific CVE, and it is not yet on CISA's KEV list, but its elevated EPSS (36.1%, 98th percentile) and active exploitation of other Langflow vulnerabilities (e.g., CVE-2026-0768) suggest near-term exploitation risk.
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