CVE-2026-104317: CVE-2026-104317: IBM Langflow OSS 1.0.0 through 1.12.3 could allow a remote attacker who could reach the me…

CVE-2026-104317 at a glance

CVE-2026-104317 is a critical-severity Deserialization vulnerability in Langflow, with a CVSS 3.1 base score of 9.8. NVD published it on 2026-10-29 and classifies the weakness as CWE-502. FIRST EPSS puts the probability of exploitation activity in the next 30 days at 0.59% (percentile 48.3, scored 2026-11-03). NVD configuration data lists a fixed release for 1 product, for example langflow langflow 1.12.4. CVERadar maps 3 MITRE ATT&CK techniques across Initial Access and Execution, inferred from the CWE and the description. Its CVERadar threat level is 49/100.

What it is

IBM Langflow OSS 1.0.0 through 1.12.3 could allow a remote attacker who could reach the message broker to execute arbitrary code on the system due to the deserialization of untrusted data.

Patches, mitigations and detection

Fixed versions

• langflow langflow: upgrade to 1.12.4 or later (affected from 1.0.0)

Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.

Vendor advisories and patches

• Vendor advisory (ibm.com) (Patch, Vendor Advisory)

MITRE ATT&CK mitigations for this chain

• M1048 Application Isolation and Sandboxing (for T1190, T1203) : Application isolation will limit what other processes and system features the exploited target can access.
• M1037 Filter Network Traffic (for T1190) : Restrict outbound network traffic from public-facing servers to prevent unauthorized connections from initiating communications with attacker-controlled infrastructure. While this may not prevent the initial exploitation, it limits the attacker's ability to verify and control the compromised server post-exploit, reduci
• M1030 Network Segmentation (for T1190) : Segment externally facing servers and services from the rest of the network with a DMZ or on separate hosting infrastructure.
• M1016 Vulnerability Scanning (for T1190) : Regularly scan externally facing systems for vulnerabilities and establish procedures to rapidly patch systems when critical vulnerabilities are discovered through scanning and through public disclosure.
• M1026 Privileged Account Management (for T1190, T1059) : Use least privilege for service accounts will limit what permissions the exploited process gets on the rest of the system.
• M1050 Exploit Protection (for T1190, T1203) : Web Application Firewalls may be used to limit exposure of applications to prevent exploit traffic from reaching the application.
• M1035 Limit Access to Resource Over Network (for T1190) : Ensure that all publicly exposed services are actually intended to be so, and restrict access to any that should only be available internally.
• M1051 Update Software (for T1190, T1203) : Update software regularly by employing patch management for externally exposed applications.
• M1033 Limit Software Installation (for T1059) : Prevent user installation of unrequired command and scripting interpreters.
• M1045 Code Signing (for T1059) : Where possible, only permit execution of signed scripts.

Detection Generic guidance

• Initial Access: Alert on unusual requests to the affected service (odd paths, oversized payloads, exploit strings) in WAF, reverse-proxy and application logs.
• Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.

Response checklist Generic guidance

1. Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
2. Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
3. Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
4. Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.