Path traversal arbitrary file write in Fluentd `${tag}` placeholder (CVE-2026-44024)

Fluentd's validation of the `${tag}` placeholder used in file path construction is insufficient. When a Fluentd instance receives logs from untrusted sources and uses `${tag}` in output plugin path parameters such as `out_file`, an attacker can inject path traversal sequences (e.g., `../`) to write or overwrite arbitrary files on the system with attacker-controlled content. This can be escalated to full remote code execution without authentication by overwriting critical system files, plugins, or configuration files. Affected versions: - <= 1.19.2 We recommend updating to: 1.19.3. CVSS 9.8 · our assessment: act_now Reference: https://github.com/fluent/fluentd/security/advisories/GHSA-44hj-4m45-frj3 Details: https://vuln.today/cve/CVE-2026-44024