CVE-2025-12970 is a stack-based buffer overflow vulnerability identified in the extract_name function within the in_docker input plugin of Fluent Bit, an open-source log processor commonly used in containerized environments. The vulnerability stems from the function copying container names into a fixed-size stack buffer without validating the length of the input. Since container names can be controlled or created by an attacker with the ability to deploy containers, supplying an excessively long container name can overflow the buffer. This overflow can corrupt the stack, potentially allowing an attacker to execute arbitrary code within the Fluent Bit process context or cause a denial of service via process crash. The CVSS 3.1 score of 8.8 reflects the high impact on confidentiality, integrity, and availability, with an attack vector over the network, low attack complexity, and requiring only low privileges but no user interaction. The vulnerability affects all versions of Fluent Bit prior to the fix (affectedVersions listed as 0 likely means all prior versions). No patches or exploits are currently publicly available, but the risk is significant given Fluent Bit’s widespread use in cloud-native logging pipelines. Exploitation could lead to compromise of logging infrastructure, data leakage, or disruption of monitoring capabilities.

For European organizations, this vulnerability poses a serious risk to containerized environments where Fluent Bit is deployed for log aggregation and processing. Successful exploitation could allow attackers to execute arbitrary code, potentially leading to unauthorized access to sensitive log data, manipulation or deletion of logs, and disruption of monitoring systems critical for security and compliance. This can impair incident detection and response capabilities, increasing the risk of undetected breaches. Industries with stringent data protection requirements, such as finance, healthcare, and critical infrastructure, could face regulatory and operational consequences. The vulnerability’s network attack vector and low privilege requirement mean that even internal threat actors or compromised containers could exploit it, increasing the attack surface. Additionally, disruption of logging services could impact forensic investigations and compliance reporting under GDPR and other regulations.

European organizations should immediately audit their Fluent Bit deployments to identify affected versions and usage of the in_docker input plugin. Since no official patches are listed yet, temporary mitigations include restricting the ability to create or rename containers with untrusted or excessively long names, enforcing container name length policies at the orchestration or container runtime level. Implement runtime protections such as stack canaries, address space layout randomization (ASLR), and control flow integrity (CFI) to reduce exploitation risk. Monitor container creation events and Fluent Bit logs for anomalous container names or crashes. Consider isolating Fluent Bit processes with minimal privileges and using container security tools to limit lateral movement. Stay alert for vendor patches or updates and apply them promptly once available. Incorporate this vulnerability into incident response plans and threat hunting activities targeting container environments.