CVE-2026-119728 in Red Hat
Summary
by MITRE • 10/30/2026
A flaw was found in the H.264 video parser in gst-plugins-bad. When processing a specially crafted H.264 video file with malformed Multiview (MVC) Sequence Parameter Set data, the parser can dereference a NULL pointer during the cleanup of partially allocated internal structures after a parse failure. This can cause the application using GStreamer to crash, resulting in a denial of service.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/30/2026
The vulnerability identified within the H.264 video parser component of gst-plugins-bad represents a critical memory management flaw that compromises the stability and availability of applications relying on this multimedia framework. The core issue stems from improper handling of malformed input data, specifically when processing H.264 files containing corrupted Multiview Coding MVC Sequence Parameter Set structures. During the parsing process, if the parser encounters invalid or unexpected data within these sequence parameter sets, it triggers an error condition that necessitates the cleanup of partially allocated internal memory structures. However, due to a logical defect in the error handling routine, the code attempts to dereference a NULL pointer during this cleanup phase rather than safely checking for nullity before access. This specific failure mode leads directly to a segmentation fault or similar critical application crash, effectively rendering the processing pipeline unusable until restart is forced by external means.
From a technical perspective, this flaw aligns with Common Weakness Enumeration category CWE-476, which describes NULL Pointer Dereference vulnerabilities. The root cause lies in the absence of defensive programming practices during resource deallocation after a parsing failure. When the parser detects malformed MVC data, it initiates an abort sequence that assumes certain internal pointers remain valid for cleanup operations. In reality, because the allocation process was interrupted or failed partway through due to the invalid input, these pointers are left in an uninitialized or null state. The subsequent attempt to free or access memory at this NULL address violates standard C programming safety protocols and results in immediate termination of the host application. This type of vulnerability is particularly dangerous in multimedia frameworks because they often process untrusted media files received from external sources, making them prime targets for exploitation by attackers seeking to disrupt services through simple file uploads or stream injection.
The operational impact of this vulnerability is primarily a denial of service against any software that integrates GStreamer and utilizes the bad plugins for H.264 decoding. Since video processing pipelines are often central to streaming servers, media players, surveillance systems, and real-time communication applications, crashing these services can lead to significant downtime and loss of functionality. An attacker does not need authentication or complex exploit chains; a single specially crafted H.264 file with malformed MVC sequence parameter sets is sufficient to trigger the crash. This simplicity lowers the barrier for entry significantly, allowing even novice attackers to cause service disruption. In environments where high availability is critical, such as live broadcasting platforms or security monitoring centers, this vulnerability poses a substantial risk to business continuity and operational reliability.
Mitigation strategies should focus on both immediate patching and long-term architectural improvements. The primary remediation step is to update the gst-plugins-bad package to a version that includes patches for this NULL pointer dereference issue. Developers maintaining applications built with GStreamer must ensure their dependency management systems are configured to pull these security updates automatically or manually apply them as soon as they become available from official distribution channels. Beyond patching, developers should review code paths involving media parsing and implement stricter input validation before passing data to the parser. Additionally, adopting memory-safe languages for new development efforts can prevent such classes of vulnerabilities in future iterations. Security teams should also monitor for any attempts to upload or stream malformed H.264 files as part of intrusion detection rules, treating them as potential indicators of compromise targeting this specific weakness.
This vulnerability is categorized under the MITRE ATT&CK framework technique T1499, Endpoint Denial of Service, specifically within the subcategory of Resource Exhaustion via Crash or Overload. By exploiting this flaw, an adversary can effectively disable endpoint capabilities without needing to escalate privileges or install persistent malware. The simplicity of the attack vector means that automated scanning tools could potentially identify vulnerable systems by sending crafted payloads and observing for crashes in logging mechanisms. Therefore, proactive vulnerability management programs must prioritize testing media processing components against malformed inputs to ensure resilience against such denial-of-service attacks. Regular security audits focusing on error handling paths in multimedia libraries are essential to prevent similar NULL pointer dereferences from persisting in production environments.