CVE-2026-73198 in FreeIPA
Summary
by MITRE • 08/20/2026
A flaw was found in FreeIPA. A remote, unauthenticated attacker can exploit a vulnerability in the `/ipa/i18n_messages` endpoint by sending an arbitrarily large request body. This can cause the service to consume excessive memory, leading to memory exhaustion, degraded responsiveness, and a denial of service (DoS) condition.
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Analysis
by VulDB Data Team • 08/20/2026
The identified vulnerability resides within the FreeIPA identity management platform, specifically targeting the `/ipa/i18n_messages` endpoint which is responsible for handling internationalization message retrieval. This component allows remote, unauthenticated actors to interact with the server by submitting requests that trigger internal processing of localization data. The core technical flaw lies in the absence of strict input validation and size constraints on the request body sent to this specific API route. When an attacker transmits a payload with an arbitrarily large volume of data, the FreeIPA service attempts to process or buffer this excessive information without adequate safeguards against memory allocation limits. This lack of rate limiting or content length enforcement creates a direct pathway for resource exhaustion attacks, where the server's available memory is rapidly depleted by the oversized input.
From an operational perspective, the exploitation of this flaw results in significant degradation of service availability and stability. As the application consumes excessive amounts of system memory to handle the malformed request, it leads to memory exhaustion conditions that can cause the FreeIPA process to crash or become unresponsive. This constitutes a classic denial-of-service scenario where legitimate users are unable to access identity management services such as user authentication, group management, or certificate issuance. The impact extends beyond simple downtime; in production environments running on constrained resources, this vulnerability could destabilize not only the FreeIPA service itself but potentially affect other co-located applications sharing the same host infrastructure due to overall system resource contention caused by the memory leak induced by the attack vector.
This vulnerability aligns with CWE-400, which describes conditions where a process consumes an unbounded amount of resources, leading to denial-of-service scenarios. It also maps closely to ATT&CK technique T1498, specifically Network Denial of Service via resource exhaustion through volumetric attacks or inefficient processing logic. The attack vector is classified as remote and unauthenticated, which significantly increases the risk profile since no prior access credentials are required to initiate the exploit. This characteristic makes it particularly dangerous in internet-facing deployments where such endpoints might be inadvertently exposed without proper network-level filtering or Web Application Firewall rules that inspect request body sizes before they reach the application layer.
Mitigation strategies should focus on implementing strict input validation and resource management controls at multiple layers of the infrastructure. At the application level, developers must enforce maximum payload size limits for all API endpoints, particularly those handling user-supplied data like localization messages. Implementing streaming processing rather than buffering entire request bodies into memory can also prevent excessive allocation during high-volume inputs. Network-level defenses should be configured to drop or rate-limit requests that exceed defined thresholds for body length before they reach the FreeIPA service. Additionally, deploying a Web Application Firewall with rules specifically targeting oversized POST requests to identity management endpoints provides an essential layer of protection against this type of volumetric abuse until software patches are applied and deployed across all affected instances.