CVE-2026-73197 in FreeIPA
Summary
by MITRE • 08/20/2026
A flaw was found in FreeIPA. A remote, unauthenticated attacker can exploit this vulnerability by sending oversized form POST requests to the `/ipa/migration/migration.py` endpoint. This can force the migration handler to read attacker-controlled request bodies fully into memory, leading to increased memory usage, slower request handling, and potential service disruption or denial of service.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/20/2026
The identified vulnerability resides within the FreeIPA identity management solution, specifically targeting the `/ipa/migration/migration.py` endpoint which is responsible for processing migration data from external directories into the IPA domain. This flaw represents a classic resource exhaustion issue where the application fails to implement adequate limits on the size of incoming request bodies before they are processed by the server's memory allocation routines. The core technical deficiency lies in the handling of HTTP POST requests, particularly those with large content lengths or oversized form data payloads. When an unauthenticated remote attacker sends these excessively large requests, the migration handler is compelled to load the entire body into system memory simultaneously rather than processing it in a streaming fashion or validating its size prior to allocation. This architectural oversight allows for significant resource consumption relative to the computational effort required by the client, creating an asymmetric attack vector that can be exploited with minimal resources on the attacker's side while imposing heavy loads on the target infrastructure.
From a security classification perspective, this vulnerability aligns closely with CWE-400, which describes Uncontrolled Resource Consumption, and more specifically CWE-787: Out-of-bounds Write if the memory allocation leads to buffer overflows in lower-level libraries, though primarily it manifests as CWE-770: Allocation of Resources Without Limits or Throttling. In terms of adversarial tactics, this behavior is consistent with techniques found in the MITRE ATT&CK framework under Resource Hijacking and Denial of Service categories, where an attacker aims to degrade service availability by consuming critical system resources such as RAM and CPU cycles. The lack of authentication requirement for this specific endpoint exacerbates the risk, allowing any external actor on the network to initiate these resource-draining requests without needing valid credentials or prior interaction with the system.
The operational impact of exploiting this vulnerability is primarily centered around service degradation and potential denial of service conditions. As the server processes multiple oversized POST requests concurrently, memory usage spikes dramatically, potentially exhausting available heap space or triggering garbage collection storms that freeze application threads. This leads to increased latency for legitimate administrative operations, timeouts on other API endpoints due to thread pool exhaustion, and in severe cases, a complete crash of the FreeIPA service process requiring manual restarts. For organizations relying on FreeIPA for centralized authentication and authorization across their enterprise infrastructure, such disruptions can halt user logins, break access control policies, and impede critical identity management workflows until the service is restored.
Mitigation strategies should focus on implementing strict input validation and resource limits at both the web server level and within the application code itself. Administrators are advised to configure reverse proxies or load balancers in front of FreeIPA to enforce maximum request body size restrictions, effectively dropping oversized payloads before they reach the Python migration handler. Additionally, updating to a patched version of FreeIPA that includes fixes for this specific endpoint is essential if available from the vendor. If immediate patching is not feasible, network-level access control lists should be applied to restrict who can send POST requests to the `/ipa/migration/` path, ensuring only trusted internal systems or authorized migration tools can interact with it. Monitoring solutions should also be tuned to detect anomalous spikes in memory usage associated with high-volume POST traffic to this specific URI pattern.