CVE-2026-93447 in Langflow OSS
Summary
by MITRE • 10/07/2026
IBM Langflow OSS 1.0.0 through 1.12.2 could allow an attacker with access to the server secret and Redis write access to submit a malicious serialized cache value. When the value was retrieved, deserialization could have executed attacker-controlled code with the privileges of the service process.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified in IBM Langflow versions 1.0.0 through 1.12.2 represents a critical insecure deserialization flaw that stems from improper validation and sanitization of cached data structures. This issue specifically affects systems where an attacker has obtained access to the server secret key and possesses write permissions to the Redis instance used for caching operations. The core technical failure lies in the application's reliance on Python's pickle module or similar serialization mechanisms without adequate safeguards against malicious payload injection. When a user submits a cache value, the system stores it directly into Redis. Later, when this cached data is retrieved by the Langflow service process, it undergoes automatic deserialization to reconstruct the original object state for use within the application logic.
The operational impact of this vulnerability is severe due to its potential for Remote Code Execution with elevated privileges. Because the deserialization occurs within the context of the running service process, any code executed during the reconstruction of the malicious serialized object inherits the permissions and security context of that process. This means an attacker who successfully exploits this flaw can execute arbitrary commands on the host system, potentially leading to full compromise of the underlying infrastructure. The requirement for both server secret access and Redis write access defines a specific attack vector where the threat actor must have already breached certain perimeter defenses or gained local access sufficient to manipulate these components. This scenario highlights the danger of trusting data sources that are not strictly controlled by the application itself, even if those sources appear benign like cache stores.
From an industry standards perspective, this vulnerability aligns with CWE-502, which describes Deserialization of Untrusted Data. It also maps closely to MITRE ATT&CK technique T1648, specifically leveraging Supplied Property in Serialized Objects for code execution. The exploitation path involves the attacker crafting a serialized object containing malicious payloads that trigger unintended side effects during the deserialization process, such as instantiating classes with dangerous methods or invoking system commands. This type of attack is particularly insidious because it bypasses traditional input validation checks by exploiting the internal mechanics of how data structures are reconstructed in memory rather than through direct API inputs.
Mitigation strategies for this vulnerability must focus on breaking the chain of trust between untrusted cache data and the application's execution environment. The most effective immediate remediation is to upgrade IBM Langflow to a version newer than 1.12.2, where these deserialization practices have likely been corrected or replaced with safer alternatives such as JSON serialization for non-critical state management. For environments that cannot immediately patch, restricting Redis write access to only trusted internal services and ensuring the server secret remains confidential are critical defensive measures. Additionally, implementing strict allow-listing of serializable classes can prevent the instantiation of arbitrary objects during deserialization. Network segmentation should also be enforced to limit an attacker's ability to interact with both the application backend and the cache infrastructure simultaneously, thereby reducing the attack surface available for this specific exploitation path.