CVE-2026-112214 in Red Hat
Summary
by MITRE • 10/19/2026
A flaw was found in the GStreamer ASF demuxer in gst-plugins-ugly. When parsing a Simple Index object, an attacker-controlled entry count is used to size a heap allocation without being limited to the payload available in the object. Processing a crafted ASF, WMV, or WMA file can cause a very large memory allocation request and lead to denial of service if the allocation fails or the process is memory-constrained.
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Analysis
by VulDB Data Team • 10/19/2026
The vulnerability identified within the GStreamer multimedia framework specifically targets the Advanced Systems Format demuxer located in the gst-plugins-ugly component. This flaw arises during the parsing phase when handling Simple Index objects, which are critical structures used to define media track locations and timing information within ASF, WMV, or WMA files. The core technical deficiency lies in the absence of a bounds check on an attacker-controlled entry count field before it is utilized to determine the size of a heap allocation. In standard operation, demuxers must validate that metadata fields such as index counts are consistent with the actual data payload available within the file structure. However, this implementation fails to verify whether the specified number of entries exceeds what can be reasonably supported by the file's content or system resources, allowing an adversary to inject a maliciously crafted value into these files.
When a victim application processes a specially constructed ASF, WMV, or WMA file containing this malformed index object, the demuxer attempts to allocate memory based on the unvalidated entry count. Because there is no upper limit imposed on this allocation request relative to the available payload size, an attacker can specify an excessively large number of entries. This triggers a heap allocation that may far exceed the system's physical memory or virtual address space limits. If the operating system cannot fulfill such a massive memory request due to resource exhaustion, the allocation fails. In many software implementations, particularly those not explicitly designed for robust error handling in this specific context, a failed critical allocation can lead directly to process termination or an unhandled exception state. Consequently, even if the application does not crash immediately, the attempt consumes significant system resources and processing time, effectively rendering the media player or any GStreamer-based service unavailable for legitimate tasks.
The operational impact of this vulnerability is primarily categorized as a denial of service against both end-user applications and server-side services that process multimedia content. For desktop users, opening a malicious file can cause their media player to freeze or crash, disrupting workflow and potentially causing data loss if unsaved work was in progress. In more severe scenarios involving servers or automated systems that ingest user-uploaded video files for transcoding, streaming, or analysis, this vulnerability allows remote attackers to exhaust server memory resources. This resource exhaustion can lead to service outages affecting multiple users sharing the same infrastructure. The attack vector is typically network-based if the vulnerable software processes untrusted media from online sources, making it a significant risk in content delivery networks and social media platforms that handle video uploads without rigorous sanitization of metadata structures.
From a classification perspective, this vulnerability aligns with CWE-789: Memory Allocation with Uncontrolled Number Which Can Lead to Denial of Service. The root cause is the failure to perform adequate input validation on data derived from external sources before using it for resource allocation decisions. Furthermore, in terms of offensive security frameworks such as MITRE ATT&CK, this behavior relates to techniques involving resource exhaustion and denial of service attacks. Attackers leverage these flaws not necessarily to gain unauthorized access or execute code, but to disrupt availability, which is a critical component of the CIA triad. The lack of validation on the index entry count represents a fundamental oversight in secure coding practices where assumptions about input size are made without verification against system constraints or logical limits defined by the file format specification.
Mitigation strategies for this vulnerability require both immediate patching and long-term architectural improvements within GStreamer projects. Developers must apply security patches that introduce strict bounds checking on all integer values used to determine memory allocation sizes, particularly those extracted from container metadata like ASF index entries. Input validation should ensure that the requested number of elements does not exceed a predefined maximum threshold consistent with reasonable file structures or available system resources. Additionally, implementing checks for potential integer overflows during size calculations is essential to prevent wrap-around errors that could result in undersized allocations leading to buffer overruns, although this specific flaw manifests as an oversized allocation request. For users unable to immediately update their software, restricting the types of media files accepted by applications or deploying web application firewalls capable of detecting anomalous file structures can provide a layer of defense against exploitation attempts until the underlying code is remediated.