CVE-2026-40005 -- CVSS 9.1 Vulnerability Briefing

CVE-2026-40005 | CVSS 9.1 (Critical) | Exploit: No known exploit

What Is It

CVE-2026-40005 is a path traversal vulnerability in Apache IoTDB that allows an attacker to write arbitrary files to any location accessible by the IoTDB process on the underlying host system.

Technical Detail

The flaw stems from improper restriction of user-supplied pathname input, a classic CWE-22 condition in which the application fails to sanitize directory traversal sequences before using them in file write operations. An attacker who can submit crafted input to the affected IoTDB interface can escape the intended working directory and write files to arbitrary locations where the IoTDB process holds write permissions. Depending on process privileges and the target environment, successful exploitation could enable configuration tampering, planting of malicious scripts, or in scenarios where the process runs with elevated rights, full system compromise through overwriting of sensitive system files or scheduled task definitions.

Exploitation Status

No known exploit code has been publicly observed or confirmed as of July 17, 2026. This vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The exploit maturity is currently assessed as no known exploit, meaning no public proof-of-concept or operational tooling has been identified at this time. However, the CVSS score of 9.1 Critical reflects the severity of potential impact if exploitation were to occur, and the straightforward nature of path traversal vulnerabilities means development of working exploits is generally not technically complex.

Who Is Targeting This

No specific threat actor attribution at this time. Neither confirmed nor reported threat actor associations have been established for this CVE. Organizations operating Apache IoTDB deployments, particularly in industrial, manufacturing, or smart infrastructure environments where IoTDB is commonly used for time-series data management, should treat this as a high-priority unattributed risk rather than waiting for actor-specific intelligence before acting.

What To Do

Apply the vendor-supplied patch from the Apache IoTDB project as soon as it becomes available, prioritizing any internet-facing or network-accessible IoTDB instances. In the interim, restrict network access to IoTDB services using firewall rules or network segmentation to limit exposure to trusted hosts only. Ensure the IoTDB process runs under a least-privilege service account with write permissions scoped strictly to required directories, which limits the blast radius of any successful exploitation. Monitor file system activity on IoTDB hosts for unexpected writes outside of designated data directories, and review IoTDB access logs for anomalous or malformed path inputs. Confirm the installed version against the affected version range published in the Apache IoTDB security advisory and do not delay patching given the critical severity rating.